21053612 has 24 divisors (see below), whose sum is σ = 37573536. Its totient is φ = 10320768.

The previous prime is 21053609. The next prime is 21053639. The reversal of 21053612 is 21635012.

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, 56258 + ... + 56630.

It is an arithmetic number, because the mean of its divisors is an integer number (1565564).

Almost surely, 2^21053612 is an apocalyptic number.

It is an amenable number.

21053612 is a deficient number, since it is larger than the sum of its proper divisors (16519924).

21053612 is a wasteful number, since it uses less digits than its factorization.

21053612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 617 (or 615 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 21053612 is about 4588.4215150747. The cubic root of 21053612 is about 276.1269981951.

Adding to 21053612 its reverse (21635012), we get a palindrome (42688624).

The spelling of 21053612 in words is "twenty-one million, fifty-three thousand, six hundred twelve".