161517856 has 24 divisors (see below), whose sum is σ = 318287340. Its totient is φ = 80683008.

The previous prime is 161517821. The next prime is 161517859. The reversal of 161517856 is 658715161.

It can be written as a sum of positive squares in 2 ways, for example, as 95648400 + 65869456 = 9780^2 + 8116^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (161517859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49920 + ... + 53056.

Almost surely, 2^161517856 is an apocalyptic number.

161517856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

161517856 is a deficient number, since it is larger than the sum of its proper divisors (156769484).

161517856 is a wasteful number, since it uses less digits than its factorization.

161517856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4756 (or 4748 counting only the distinct ones).

The product of its digits is 50400, while the sum is 40.

The square root of 161517856 is about 12708.9675426448. The cubic root of 161517856 is about 544.5948294585.

The spelling of 161517856 in words is "one hundred sixty-one million, five hundred seventeen thousand, eight hundred fifty-six".