165539057531 has 2 divisors, whose sum is σ = 165539057532. Its totient is φ = 165539057530.

The previous prime is 165539057513. The next prime is 165539057581. The reversal of 165539057531 is 135750935561.

Together with previous prime (165539057513) it forms an Ormiston pair, because they use the same digits, order apart.

It is an a-pointer prime, because the next prime (165539057581) can be obtained adding 165539057531 to its sum of digits (50).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165539057531 is a prime.

It is a super-2 number, since 2×165539057531² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 165539057531.

It is not a weakly prime, because it can be changed into another prime (165539057581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82769528765 + 82769528766.

It is an arithmetic number, because the mean of its divisors is an integer number (82769528766).

Almost surely, 2^165539057531 is an apocalyptic number.

165539057531 is a deficient number, since it is larger than the sum of its proper divisors (1).

165539057531 is an equidigital number, since it uses as much as digits as its factorization.

165539057531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2126250, while the sum is 50.

The spelling of 165539057531 in words is "one hundred sixty-five billion, five hundred thirty-nine million, fifty-seven thousand, five hundred thirty-one".