161635256517 has 16 divisors (see below), whose sum is σ = 251541798912. Its totient is φ = 90397832880.

The previous prime is 161635256501. The next prime is 161635256533. The reversal of 161635256517 is 715652536161.

It is an interprime number because it is at equal distance from previous prime (161635256501) and next prime (161635256533).

It is not a de Polignac number, because 161635256517 - 2⁴ = 161635256501 is a prime.

It is a super-2 number, since 2×161635256517² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161635256537) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 81881109 + ... + 81883082.

It is an arithmetic number, because the mean of its divisors is an integer number (15721362432).

Almost surely, 2^161635256517 is an apocalyptic number.

It is an amenable number.

161635256517 is a deficient number, since it is larger than the sum of its proper divisors (89906542395).

161635256517 is a wasteful number, since it uses less digits than its factorization.

161635256517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163764248.

The product of its digits is 1134000, while the sum is 48.

The spelling of 161635256517 in words is "one hundred sixty-one billion, six hundred thirty-five million, two hundred fifty-six thousand, five hundred seventeen".