21355473137065 has 32 divisors (see below), whose sum is σ = 26612644939776. Its totient is φ = 16438479805440.

The previous prime is 21355473137039. The next prime is 21355473137129. The reversal of 21355473137065 is 56073137455312.

It is not a de Polignac number, because 21355473137065 - 2²¹ = 21355471039913 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 479800542 + ... + 479845048.

It is an arithmetic number, because the mean of its divisors is an integer number (831645154368).

Almost surely, 2^{21355473137065} is an apocalyptic number.

It is an amenable number.

21355473137065 is a deficient number, since it is larger than the sum of its proper divisors (5257171802711).

21355473137065 is a wasteful number, since it uses less digits than its factorization.

21355473137065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76689.

The product of its (nonzero) digits is 7938000, while the sum is 52.

The spelling of 21355473137065 in words is "twenty-one trillion, three hundred fifty-five billion, four hundred seventy-three million, one hundred thirty-seven thousand, sixty-five".