165662681 has 2 divisors, whose sum is σ = 165662682. Its totient is φ = 165662680.

The previous prime is 165662663. The next prime is 165662687. The reversal of 165662681 is 186266561.

It is a happy number.

165662681 is nontrivially palindromic in base 16.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 154878025 + 10784656 = 12445^2 + 3284^2 .

It is a cyclic number.

It is not a de Polignac number, because 165662681 - 2¹⁴ = 165646297 is a prime.

It is a super-2 number, since 2×165662681² = 54888247752215522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (165662687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82831340 + 82831341.

It is an arithmetic number, because the mean of its divisors is an integer number (82831341).

Almost surely, 2^165662681 is an apocalyptic number.

It is an amenable number.

165662681 is a deficient number, since it is larger than the sum of its proper divisors (1).

165662681 is an equidigital number, since it uses as much as digits as its factorization.

165662681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 41.

The square root of 165662681 is about 12871.0015538807. The cubic root of 165662681 is about 549.2139526164.

The spelling of 165662681 in words is "one hundred sixty-five million, six hundred sixty-two thousand, six hundred eighty-one".