28574921 has 4 divisors (see below), whose sum is σ = 28586112. Its totient is φ = 28563732.

The previous prime is 28574893. The next prime is 28574957. The reversal of 28574921 is 12947582.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28574921 - 2²² = 24380617 is a prime.

It is a super-2 number, since 2×28574921² = 1633052220312482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28574321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 320 + ... + 7566.

It is an arithmetic number, because the mean of its divisors is an integer number (7146528).

Almost surely, 2^28574921 is an apocalyptic number.

It is an amenable number.

28574921 is a deficient number, since it is larger than the sum of its proper divisors (11191).

28574921 is an equidigital number, since it uses as much as digits as its factorization.

28574921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11190.

The product of its digits is 40320, while the sum is 38.

The square root of 28574921 is about 5345.5515150450. The cubic root of 28574921 is about 305.7231644082.

The spelling of 28574921 in words is "twenty-eight million, five hundred seventy-four thousand, nine hundred twenty-one".