15972138 has 96 divisors (see below), whose sum is σ = 43680000. Its totient is φ = 4191264.

The previous prime is 15972119. The next prime is 15972149. The reversal of 15972138 is 83127951.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 80163 + ... + 80361.

It is an arithmetic number, because the mean of its divisors is an integer number (455000).

Almost surely, 2^15972138 is an apocalyptic number.

15972138 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 15972138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21840000).

15972138 is an abundant number, since it is smaller than the sum of its proper divisors (27707862).

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

15972138 is a wasteful number, since it uses less digits than its factorization.

15972138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241 (or 224 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 15972138 is about 3996.5157324850. The cubic root of 15972138 is about 251.8378586607.

It can be divided in two parts, 15972 and 138, that added together give a triangular number (16110 = T₁₇₉).

The spelling of 15972138 in words is "fifteen million, nine hundred seventy-two thousand, one hundred thirty-eight".