21055012 has 12 divisors (see below), whose sum is σ = 40196016. Its totient is φ = 9570440.

The previous prime is 21055003. The next prime is 21055033.

21055012 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 239218 + ... + 239305.

It is an arithmetic number, because the mean of its divisors is an integer number (3349668).

Almost surely, 2^21055012 is an apocalyptic number.

21055012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21055012 is a deficient number, since it is larger than the sum of its proper divisors (19141004).

21055012 is a wasteful number, since it uses less digits than its factorization.

21055012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478538 (or 478536 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 21055012 is about 4588.5740704493. The cubic root of 21055012 is about 276.1331185895.

It can be divided in two parts, 2105 and 5012, that added together give a palindrome (7117).

The spelling of 21055012 in words is "twenty-one million, fifty-five thousand, twelve".