21065902 has 32 divisors (see below), whose sum is σ = 37668960. Its totient is φ = 8709120.

The previous prime is 21065899. The next prime is 21065911. The reversal of 21065902 is 20956012.

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 in 15 ways as a sum of consecutive naturals, for example, 20374 + ... + 21382.

It is an arithmetic number, because the mean of its divisors is an integer number (1177155).

Almost surely, 2^21065902 is an apocalyptic number.

21065902 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21065902 is a deficient number, since it is larger than the sum of its proper divisors (16603058).

21065902 is a wasteful number, since it uses less digits than its factorization.

21065902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1108.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21065902 is about 4589.7605602035. The cubic root of 21065902 is about 276.1807172542.

It can be divided in two parts, 2106 and 5902, that added together give a palindrome (8008).

The spelling of 21065902 in words is "twenty-one million, sixty-five thousand, nine hundred two".