161491517 has 32 divisors (see below), whose sum is σ = 195592320. Its totient is φ = 131604480.

The previous prime is 161491511. The next prime is 161491553. The reversal of 161491517 is 715194161.

It is not a de Polignac number, because 161491517 - 2⁴ = 161491501 is a prime.

It is a super-2 number, since 2×161491517² = 52159020125922578, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161491511) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 525878 + ... + 526184.

It is an arithmetic number, because the mean of its divisors is an integer number (6112260).

Almost surely, 2^161491517 is an apocalyptic number.

161491517 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

161491517 is a deficient number, since it is larger than the sum of its proper divisors (34100803).

161491517 is a wasteful number, since it uses less digits than its factorization.

161491517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461.

The product of its digits is 7560, while the sum is 35.

The square root of 161491517 is about 12707.9312635850. The cubic root of 161491517 is about 544.5652251713.

The spelling of 161491517 in words is "one hundred sixty-one million, four hundred ninety-one thousand, five hundred seventeen".