165716640 has 144 divisors (see below), whose sum is σ = 569886408. Its totient is φ = 43849728.

The previous prime is 165716609. The next prime is 165716671. The reversal of 165716640 is 46617561.

165716640 is a `hidden beast` number, since 1 + 6 + 5 + 7 + 1 + 6 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (165716609) and next prime (165716671).

It can be written as a sum of positive squares in 4 ways, for example, as 155451024 + 10265616 = 12468^2 + 3204^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 165716595 and 165716604.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 225714 + ... + 226446.

Almost surely, 2^165716640 is an apocalyptic number.

165716640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165716640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (284943204).

165716640 is an abundant number, since it is smaller than the sum of its proper divisors (404169768).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165716640 is a wasteful number, since it uses less digits than its factorization.

165716640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 911 (or 900 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 165716640 is about 12873.0975293439. The cubic root of 165716640 is about 549.2735754164.

The spelling of 165716640 in words is "one hundred sixty-five million, seven hundred sixteen thousand, six hundred forty".