21620614317765 has 16 divisors (see below), whose sum is σ = 34641095558400. Its totient is φ = 11514956752832.

The previous prime is 21620614317761. The next prime is 21620614317769. The reversal of 21620614317765 is 56771341602612.

It is an interprime number because it is at equal distance from previous prime (21620614317761) and next prime (21620614317769).

It is a cyclic number.

It is not a de Polignac number, because 21620614317765 - 2² = 21620614317761 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620614317761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1002335730 + ... + 1002357299.

It is an arithmetic number, because the mean of its divisors is an integer number (2165068472400).

Almost surely, 2^{21620614317765} is an apocalyptic number.

It is an amenable number.

21620614317765 is a deficient number, since it is larger than the sum of its proper divisors (13020481240635).

21620614317765 is a wasteful number, since it uses less digits than its factorization.

21620614317765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2004693756.

The product of its (nonzero) digits is 2540160, while the sum is 51.

The spelling of 21620614317765 in words is "twenty-one trillion, six hundred twenty billion, six hundred fourteen million, three hundred seventeen thousand, seven hundred sixty-five".