21157736315 has 8 divisors (see below), whose sum is σ = 25406435808. Its totient is φ = 16914754240.

The previous prime is 21157736293. The next prime is 21157736329. The reversal of 21157736315 is 51363775112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21157736315 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1421207 + ... + 1436016.

It is an arithmetic number, because the mean of its divisors is an integer number (3175804476).

Almost surely, 2^21157736315 is an apocalyptic number.

21157736315 is a deficient number, since it is larger than the sum of its proper divisors (4248699493).

21157736315 is a wasteful number, since it uses less digits than its factorization.

21157736315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2858709.

The product of its digits is 132300, while the sum is 41.

The spelling of 21157736315 in words is "twenty-one billion, one hundred fifty-seven million, seven hundred thirty-six thousand, three hundred fifteen".