21072108784 has 10 divisors (see below), whose sum is σ = 40827210800. Its totient is φ = 10536054384.

The previous prime is 21072108767. The next prime is 21072108851. The reversal of 21072108784 is 48780127012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 658503384 + ... + 658503415.

It is an arithmetic number, because the mean of its divisors is an integer number (4082721080).

Almost surely, 2^21072108784 is an apocalyptic number.

It is an amenable number.

21072108784 is a deficient number, since it is larger than the sum of its proper divisors (19755102016).

21072108784 is a wasteful number, since it uses less digits than its factorization.

21072108784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1317006807 (or 1317006801 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 40.

The spelling of 21072108784 in words is "twenty-one billion, seventy-two million, one hundred eight thousand, seven hundred eighty-four".