161640080 has 80 divisors (see below), whose sum is σ = 454792320. Its totient is φ = 52156416.

The previous prime is 161640071. The next prime is 161640103. The reversal of 161640080 is 80046161.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×161640080² = 52255030924812800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1031 + ... + 18009.

It is an arithmetic number, because the mean of its divisors is an integer number (5684904).

Almost surely, 2^161640080 is an apocalyptic number.

161640080 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161640080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227396160).

161640080 is an abundant number, since it is smaller than the sum of its proper divisors (293152240).

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

161640080 is a wasteful number, since it uses less digits than its factorization.

161640080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17016 (or 17010 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 161640080 is about 12713.7752064444. The cubic root of 161640080 is about 544.7321636567.

The spelling of 161640080 in words is "one hundred sixty-one million, six hundred forty thousand, eighty".