161515015281 has 8 divisors (see below), whose sum is σ = 239281504160. Its totient is φ = 107676676836.

The previous prime is 161515015247. The next prime is 161515015309. The reversal of 161515015281 is 182510515161.

161515015281 is a `hidden beast` number, since 1 + 61 + 515 + 0 + 1 + 5 + 2 + 81 = 666.

It is not a de Polignac number, because 161515015281 - 2¹⁹ = 161514490993 is a prime.

It is a super-2 number, since 2×161515015281² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161515015231) 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, 2991018775 + ... + 2991018828.

It is an arithmetic number, because the mean of its divisors is an integer number (29910188020).

Almost surely, 2^161515015281 is an apocalyptic number.

It is an amenable number.

161515015281 is a deficient number, since it is larger than the sum of its proper divisors (77766488879).

161515015281 is an equidigital number, since it uses as much as digits as its factorization.

161515015281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5982037612 (or 5982037606 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 36.

The spelling of 161515015281 in words is "one hundred sixty-one billion, five hundred fifteen million, fifteen thousand, two hundred eighty-one".