21387703564 has 24 divisors (see below), whose sum is σ = 38028538800. Its totient is φ = 10523546880.

The previous prime is 21387703559. The next prime is 21387703567. The reversal of 21387703564 is 46530778312.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21387703567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67249 + ... + 217480.

It is an arithmetic number, because the mean of its divisors is an integer number (1584522450).

Almost surely, 2^21387703564 is an apocalyptic number.

It is an amenable number.

21387703564 is a deficient number, since it is larger than the sum of its proper divisors (16640835236).

21387703564 is a wasteful number, since it uses less digits than its factorization.

21387703564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285033 (or 285031 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 46.

The spelling of 21387703564 in words is "twenty-one billion, three hundred eighty-seven million, seven hundred three thousand, five hundred sixty-four".