28390972 has 12 divisors (see below), whose sum is σ = 49739536. Its totient is φ = 14179680.

The previous prime is 28390939. The next prime is 28390979. The reversal of 28390972 is 27909382.

It is a super-2 number, since 2×28390972² = 1612094582209568, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28390979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 697 + ... + 7567.

Almost surely, 2^28390972 is an apocalyptic number.

It is an amenable number.

28390972 is a deficient number, since it is larger than the sum of its proper divisors (21348564).

28390972 is a wasteful number, since it uses less digits than its factorization.

28390972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7908 (or 7906 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 28390972 is about 5328.3179334570. The cubic root of 28390972 is about 305.0657280185.

The spelling of 28390972 in words is "twenty-eight million, three hundred ninety thousand, nine hundred seventy-two".