21046836 has 12 divisors (see below), whose sum is σ = 49109312. Its totient is φ = 7015608.

The previous prime is 21046819. The next prime is 21046841. The reversal of 21046836 is 63864012.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21046836² = 885938611221792, which contains 22 as substring.

It is a congruent number.

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, 876940 + ... + 876963.

Almost surely, 2^21046836 is an apocalyptic number.

It is an amenable number.

21046836 is an abundant number, since it is smaller than the sum of its proper divisors (28062476).

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

21046836 is a wasteful number, since it uses less digits than its factorization.

21046836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1753910 (or 1753908 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 21046836 is about 4587.6830753660. The cubic root of 21046836 is about 276.0973716508.

The spelling of 21046836 in words is "twenty-one million, forty-six thousand, eight hundred thirty-six".