21335064215664 has 40 divisors (see below), whose sum is σ = 58357675650960. Its totient is φ = 6693353479168.

The previous prime is 21335064215659. The next prime is 21335064215671. The reversal of 21335064215664 is 46651246053312.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent 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, 13072955199 + ... + 13072956830.

It is an arithmetic number, because the mean of its divisors is an integer number (1458941891274).

Almost surely, 2^{21335064215664} is an apocalyptic number.

21335064215664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21335064215664 is an abundant number, since it is smaller than the sum of its proper divisors (37022611435296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21335064215664 is a wasteful number, since it uses less digits than its factorization.

21335064215664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26145912057 (or 26145912051 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 48.

The spelling of 21335064215664 in words is "twenty-one trillion, three hundred thirty-five billion, sixty-four million, two hundred fifteen thousand, six hundred sixty-four".