161571930 has 64 divisors (see below), whose sum is σ = 422005248. Its totient is φ = 39352320.

The previous prime is 161571929. The next prime is 161571973. The reversal of 161571930 is 39175161.

It is a happy number.

It is a super-2 number, since 2×161571930² = 52210977127849800, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 161571891 and 161571900.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35695 + ... + 39965.

It is an arithmetic number, because the mean of its divisors is an integer number (6593832).

Almost surely, 2^161571930 is an apocalyptic number.

161571930 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 161571930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (211002624).

161571930 is an abundant number, since it is smaller than the sum of its proper divisors (260433318).

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

161571930 is a wasteful number, since it uses less digits than its factorization.

161571930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4391.

The product of its (nonzero) digits is 5670, while the sum is 33.

The square root of 161571930 is about 12711.0947600905. The cubic root of 161571930 is about 544.6555970125.

The spelling of 161571930 in words is "one hundred sixty-one million, five hundred seventy-one thousand, nine hundred thirty".