21312910921385 has 16 divisors (see below), whose sum is σ = 26171473166784. Its totient is φ = 16653045095232.

The previous prime is 21312910921349. The next prime is 21312910921397. The reversal of 21312910921385 is 58312901921312.

It is a cyclic number.

It is not a de Polignac number, because 21312910921385 - 2⁸ = 21312910921129 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2443034 + ... + 6970956.

It is an arithmetic number, because the mean of its divisors is an integer number (1635717072924).

Almost surely, 2^{21312910921385} is an apocalyptic number.

It is an amenable number.

21312910921385 is a deficient number, since it is larger than the sum of its proper divisors (4858562245399).

21312910921385 is a wasteful number, since it uses less digits than its factorization.

21312910921385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4549864.

The product of its (nonzero) digits is 233280, while the sum is 47.

The spelling of 21312910921385 in words is "twenty-one trillion, three hundred twelve billion, nine hundred ten million, nine hundred twenty-one thousand, three hundred eighty-five".