21506380392 has 64 divisors (see below), whose sum is σ = 61823854080. Its totient is φ = 6106974912.

The previous prime is 21506380373. The next prime is 21506380453. The reversal of 21506380392 is 29308360512.

It is a self number, because there is not a number n which added to its sum of digits gives 21506380392.

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 15 ways as a sum of consecutive naturals, for example, 365298 + ... + 420065.

It is an arithmetic number, because the mean of its divisors is an integer number (965997720).

Almost surely, 2^21506380392 is an apocalyptic number.

It is an amenable number.

21506380392 is an abundant number, since it is smaller than the sum of its proper divisors (40317473688).

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

21506380392 is a wasteful number, since it uses less digits than its factorization.

21506380392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 785542 (or 785538 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 39.

The spelling of 21506380392 in words is "twenty-one billion, five hundred six million, three hundred eighty thousand, three hundred ninety-two".