21317703896 has 16 divisors (see below), whose sum is σ = 40821135840. Its totient is φ = 10432067680.

The previous prime is 21317703881. The next prime is 21317703917. The reversal of 21317703896 is 69830771312.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a self number, because there is not a number n which added to its sum of digits gives 21317703896.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28347635 + ... + 28348386.

It is an arithmetic number, because the mean of its divisors is an integer number (2551320990).

Almost surely, 2^21317703896 is an apocalyptic number.

It is an amenable number.

21317703896 is a deficient number, since it is larger than the sum of its proper divisors (19503431944).

21317703896 is a wasteful number, since it uses less digits than its factorization.

21317703896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56696074 (or 56696070 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 47.

The spelling of 21317703896 in words is "twenty-one billion, three hundred seventeen million, seven hundred three thousand, eight hundred ninety-six".