161574138 has 96 divisors (see below), whose sum is σ = 416145600. Its totient is φ = 44755200.

The previous prime is 161574131. The next prime is 161574169. The reversal of 161574138 is 831475161.

161574138 is a `hidden beast` number, since 1 + 615 + 7 + 4 + 1 + 38 = 666.

It is a super-2 number, since 2×161574138² = 52212404140886088, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161574131) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 108358 + ... + 109838.

It is an arithmetic number, because the mean of its divisors is an integer number (4334850).

Almost surely, 2^161574138 is an apocalyptic number.

161574138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 161574138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (208072800).

161574138 is an abundant number, since it is smaller than the sum of its proper divisors (254571462).

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

161574138 is a wasteful number, since it uses less digits than its factorization.

161574138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1548 (or 1545 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 161574138 is about 12711.1816130523. The cubic root of 161574138 is about 544.6580780418.

The spelling of 161574138 in words is "one hundred sixty-one million, five hundred seventy-four thousand, one hundred thirty-eight".