161507711531 has 2 divisors, whose sum is σ = 161507711532. Its totient is φ = 161507711530.

The previous prime is 161507711509. The next prime is 161507711567. The reversal of 161507711531 is 135117705161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161507711531 - 2⁶ = 161507711467 is a prime.

It is a super-2 number, since 2×161507711531² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161507711581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80753855765 + 80753855766.

It is an arithmetic number, because the mean of its divisors is an integer number (80753855766).

Almost surely, 2^161507711531 is an apocalyptic number.

161507711531 is a deficient number, since it is larger than the sum of its proper divisors (1).

161507711531 is an equidigital number, since it uses as much as digits as its factorization.

161507711531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22050, while the sum is 38.

The spelling of 161507711531 in words is "one hundred sixty-one billion, five hundred seven million, seven hundred eleven thousand, five hundred thirty-one".