21621170502201 has 16 divisors (see below), whose sum is σ = 30891764522304. Its totient is φ = 13402776136704.

The previous prime is 21621170502179. The next prime is 21621170502221. The reversal of 21621170502201 is 10220507112612.

It is a happy number.

It is not a de Polignac number, because 21621170502201 - 2²⁷ = 21621036284473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21621170502221) 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, 2553878416 + ... + 2553886881.

It is an arithmetic number, because the mean of its divisors is an integer number (1930735282644).

Almost surely, 2^{21621170502201} is an apocalyptic number.

It is an amenable number.

21621170502201 is a deficient number, since it is larger than the sum of its proper divisors (9270594020103).

21621170502201 is a wasteful number, since it uses less digits than its factorization.

21621170502201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5107765400.

The product of its (nonzero) digits is 3360, while the sum is 30.

Adding to 21621170502201 its reverse (10220507112612), we get a palindrome (31841677614813).

The spelling of 21621170502201 in words is "twenty-one trillion, six hundred twenty-one billion, one hundred seventy million, five hundred two thousand, two hundred one".