28931572 has 6 divisors (see below), whose sum is σ = 50630258. Its totient is φ = 14465784.

The previous prime is 28931557. The next prime is 28931593. The reversal of 28931572 is 27513982.

It can be written as a sum of positive squares in only one way, i.e., 28665316 + 266256 = 5354^2 + 516^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3616443 + ... + 3616450.

Almost surely, 2^28931572 is an apocalyptic number.

It is an amenable number.

28931572 is a deficient number, since it is larger than the sum of its proper divisors (21698686).

28931572 is a wasteful number, since it uses less digits than its factorization.

28931572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7232897 (or 7232895 counting only the distinct ones).

The product of its digits is 30240, while the sum is 37.

The square root of 28931572 is about 5378.8076745688. The cubic root of 28931572 is about 306.9898457103.

It can be divided in two parts, 2893 and 1572, that added together give a triangular number (4465 = T₉₄).

The spelling of 28931572 in words is "twenty-eight million, nine hundred thirty-one thousand, five hundred seventy-two".