21620473722601 has 4 divisors (see below), whose sum is σ = 23283587085892. Its totient is φ = 19957360359312.

The previous prime is 21620473722599. The next prime is 21620473722721. The reversal of 21620473722601 is 10622737402612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1403751040000 + 20216722682601 = 1184800^2 + 4496301^2 .

It is a cyclic number.

It is not a de Polignac number, because 21620473722601 - 2¹ = 21620473722599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21620473723601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 831556681626 + ... + 831556681651.

It is an arithmetic number, because the mean of its divisors is an integer number (5820896771473).

Almost surely, 2^{21620473722601} is an apocalyptic number.

It is an amenable number.

21620473722601 is a deficient number, since it is larger than the sum of its proper divisors (1663113363291).

21620473722601 is a wasteful number, since it uses less digits than its factorization.

21620473722601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663113363290.

The product of its (nonzero) digits is 338688, while the sum is 43.

The spelling of 21620473722601 in words is "twenty-one trillion, six hundred twenty billion, four hundred seventy-three million, seven hundred twenty-two thousand, six hundred one".