161617860 has 36 divisors (see below), whose sum is σ = 490241388. Its totient is φ = 43098048.

The previous prime is 161617843. The next prime is 161617889. The reversal of 161617860 is 68716161.

It can be written as a sum of positive squares in 2 ways, for example, as 98128836 + 63489024 = 9906^2 + 7968^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×161617860² = 52240665341959200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 448759 + ... + 449118.

Almost surely, 2^161617860 is an apocalyptic number.

161617860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161617860 is an abundant number, since it is smaller than the sum of its proper divisors (328623528).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161617860 is a wasteful number, since it uses less digits than its factorization.

161617860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897892 (or 897887 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 161617860 is about 12712.9013210990. The cubic root of 161617860 is about 544.7072018127.

The spelling of 161617860 in words is "one hundred sixty-one million, six hundred seventeen thousand, eight hundred sixty".