21451304215315 has 16 divisors (see below), whose sum is σ = 27887683578048. Its totient is φ = 15746107038336.

The previous prime is 21451304215309. The next prime is 21451304215337. The reversal of 21451304215315 is 51351240315412.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21451304215315 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 988073172 + ... + 988094881.

It is an arithmetic number, because the mean of its divisors is an integer number (1742980223628).

Almost surely, 2^{21451304215315} is an apocalyptic number.

21451304215315 is a deficient number, since it is larger than the sum of its proper divisors (6436379362733).

21451304215315 is a wasteful number, since it uses less digits than its factorization.

21451304215315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1976168238.

The product of its (nonzero) digits is 72000, while the sum is 37.

The spelling of 21451304215315 in words is "twenty-one trillion, four hundred fifty-one billion, three hundred four million, two hundred fifteen thousand, three hundred fifteen".