165986440 has 32 divisors (see below), whose sum is σ = 383566680. Its totient is φ = 64599552.

The previous prime is 165986437. The next prime is 165986441. The reversal of 165986440 is 44689561.

It can be written as a sum of positive squares in 4 ways, for example, as 161137636 + 4848804 = 12694^2 + 2202^2 .

It is not an unprimeable number, because it can be changed into a prime (165986441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54597 + ... + 57556.

Almost surely, 2^165986440 is an apocalyptic number.

165986440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165986440 is an abundant number, since it is smaller than the sum of its proper divisors (217580240).

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

165986440 is a wasteful number, since it uses less digits than its factorization.

165986440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112201 (or 112197 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 43.

The square root of 165986440 is about 12883.5724859218. The cubic root of 165986440 is about 549.5715009585.

The spelling of 165986440 in words is "one hundred sixty-five million, nine hundred eighty-six thousand, four hundred forty".