21020697907065 has 24 divisors (see below), whose sum is σ = 36436245663168. Its totient is φ = 11210925255840.

The previous prime is 21020697906953. The next prime is 21020697907093. The reversal of 21020697907065 is 56070979602012.

It is not a de Polignac number, because 21020697907065 - 2⁹ = 21020697906553 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2219652 + ... + 6853338.

It is an arithmetic number, because the mean of its divisors is an integer number (1518176902632).

Almost surely, 2^{21020697907065} is an apocalyptic number.

It is an amenable number.

21020697907065 is a deficient number, since it is larger than the sum of its proper divisors (15415547756103).

21020697907065 is a wasteful number, since it uses less digits than its factorization.

21020697907065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4734509 (or 4734506 counting only the distinct ones).

The product of its (nonzero) digits is 2857680, while the sum is 54.

The spelling of 21020697907065 in words is "twenty-one trillion, twenty billion, six hundred ninety-seven million, nine hundred seven thousand, sixty-five".