21363764 has 12 divisors (see below), whose sum is σ = 39585924. Its totient is φ = 10053504.

The previous prime is 21363739. The next prime is 21363773. The reversal of 21363764 is 46736312.

It can be written as a sum of positive squares in 2 ways, for example, as 18992164 + 2371600 = 4358^2 + 1540^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21363764.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157019 + ... + 157154.

It is an arithmetic number, because the mean of its divisors is an integer number (3298827).

Almost surely, 2^21363764 is an apocalyptic number.

It is an amenable number.

21363764 is a deficient number, since it is larger than the sum of its proper divisors (18222160).

21363764 is a wasteful number, since it uses less digits than its factorization.

21363764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314194 (or 314192 counting only the distinct ones).

The product of its digits is 18144, while the sum is 32.

The square root of 21363764 is about 4622.0951959041. The cubic root of 21363764 is about 277.4763186241.

The spelling of 21363764 in words is "twenty-one million, three hundred sixty-three thousand, seven hundred sixty-four".