161978130 has 80 divisors (see below), whose sum is σ = 437621184. Its totient is φ = 42988320.

The previous prime is 161978129. The next prime is 161978147. The reversal of 161978130 is 31879161.

161978130 is a `hidden beast` number, since 1 + 619 + 7 + 8 + 1 + 30 = 666.

161978130 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 251589 + ... + 252231.

Almost surely, 2^161978130 is an apocalyptic number.

161978130 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 161978130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (218810592).

161978130 is an abundant number, since it is smaller than the sum of its proper divisors (275643054).

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

161978130 is a wasteful number, since it uses less digits than its factorization.

161978130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 973 (or 964 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 161978130 is about 12727.0628976210. The cubic root of 161978130 is about 545.1116456177. Note that the first 3 decimals are identical.

The spelling of 161978130 in words is "one hundred sixty-one million, nine hundred seventy-eight thousand, one hundred thirty".