21255004 has 6 divisors (see below), whose sum is σ = 37196264. Its totient is φ = 10627500.

The previous prime is 21254993. The next prime is 21255019. The reversal of 21255004 is 40055212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2656872 + ... + 2656879.

Almost surely, 2^21255004 is an apocalyptic number.

It is an amenable number.

21255004 is a deficient number, since it is larger than the sum of its proper divisors (15941260).

21255004 is a wasteful number, since it uses less digits than its factorization.

21255004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5313755 (or 5313753 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 21255004 is about 4610.3149567031. The cubic root of 21255004 is about 277.0046526607.

It can be divided in two parts, 21 and 255004, that added together give a square (255025 = 505²).

The spelling of 21255004 in words is "twenty-one million, two hundred fifty-five thousand, four".