165720680 has 32 divisors (see below), whose sum is σ = 375605640. Its totient is φ = 65802240.

The previous prime is 165720677. The next prime is 165720683. The reversal of 165720680 is 86027561.

It is an interprime number because it is at equal distance from previous prime (165720677) and next prime (165720683).

It can be written as a sum of positive squares in 4 ways, for example, as 111049444 + 54671236 = 10538^2 + 7394^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 165720680.

It is not an unprimeable number, because it can be changed into a prime (165720683) 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, 9641 + ... + 20600.

Almost surely, 2^165720680 is an apocalyptic number.

165720680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165720680 is an abundant number, since it is smaller than the sum of its proper divisors (209884960).

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

165720680 is a wasteful number, since it uses less digits than its factorization.

165720680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30389 (or 30385 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 165720680 is about 12873.2544447781. The cubic root of 165720680 is about 549.2780389537.

The spelling of 165720680 in words is "one hundred sixty-five million, seven hundred twenty thousand, six hundred eighty".