21259028 has 24 divisors (see below), whose sum is σ = 43509312. Its totient is φ = 8898624.

The previous prime is 21259013. The next prime is 21259037. The reversal of 21259028 is 82095212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7625 + ... + 10032.

It is an arithmetic number, because the mean of its divisors is an integer number (1812888).

Almost surely, 2^21259028 is an apocalyptic number.

21259028 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21259028 is an abundant number, since it is smaller than the sum of its proper divisors (22250284).

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

21259028 is a wasteful number, since it uses less digits than its factorization.

21259028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17711 (or 17709 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 21259028 is about 4610.7513487500. The cubic root of 21259028 is about 277.0221324094.

The spelling of 21259028 in words is "twenty-one million, two hundred fifty-nine thousand, twenty-eight".