21075764 has 12 divisors (see below), whose sum is σ = 36960000. Its totient is φ = 10515768.

The previous prime is 21075749. The next prime is 21075773. The reversal of 21075764 is 46757012.

It is a self number, because there is not a number n which added to its sum of digits gives 21075764.

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 3 ways as a sum of consecutive naturals, for example, 3284 + ... + 7275.

It is an arithmetic number, because the mean of its divisors is an integer number (3080000).

Almost surely, 2^21075764 is an apocalyptic number.

It is an amenable number.

21075764 is a deficient number, since it is larger than the sum of its proper divisors (15884236).

21075764 is a wasteful number, since it uses less digits than its factorization.

21075764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11062 (or 11060 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 21075764 is about 4590.8347824769. The cubic root of 21075764 is about 276.2238085226.

The spelling of 21075764 in words is "twenty-one million, seventy-five thousand, seven hundred sixty-four".