21002170600621 has 16 divisors (see below), whose sum is σ = 24207059683584. Its totient is φ = 17848745599104.

The previous prime is 21002170600571. The next prime is 21002170600681. The reversal of 21002170600621 is 12600607120012.

It is not a de Polignac number, because 21002170600621 - 2⁹ = 21002170600109 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21002170600621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002170600681) 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, 12515770 + ... + 14094283.

It is an arithmetic number, because the mean of its divisors is an integer number (1512941230224).

Almost surely, 2^{21002170600621} is an apocalyptic number.

It is an amenable number.

21002170600621 is a deficient number, since it is larger than the sum of its proper divisors (3204889082963).

21002170600621 is a wasteful number, since it uses less digits than its factorization.

21002170600621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26611020.

The product of its (nonzero) digits is 2016, while the sum is 28.

Adding to 21002170600621 its reverse (12600607120012), we get a palindrome (33602777720633).

The spelling of 21002170600621 in words is "twenty-one trillion, two billion, one hundred seventy million, six hundred thousand, six hundred twenty-one".