28538172 has 108 divisors (see below), whose sum is σ = 82917016. Its totient is φ = 8225280.

The previous prime is 28538161. The next prime is 28538183. The reversal of 28538172 is 27183582.

It is an interprime number because it is at equal distance from previous prime (28538161) and next prime (28538183).

It is a super-2 number, since 2×28538172² = 1628854522203168, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 135147 + ... + 135357.

Almost surely, 2^28538172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28538172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41458508).

28538172 is an abundant number, since it is smaller than the sum of its proper divisors (54378844).

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

28538172 is a wasteful number, since it uses less digits than its factorization.

28538172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268 (or 246 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 28538172 is about 5342.1130650708. The cubic root of 28538172 is about 305.5920489648.

It can be divided in two parts, 2853 and 8172, that added together give a square (11025 = 105²).

The spelling of 28538172 in words is "twenty-eight million, five hundred thirty-eight thousand, one hundred seventy-two".