21201010221021 has 16 divisors (see below), whose sum is σ = 28627000505280. Its totient is φ = 13954973028480.

The previous prime is 21201010221011. The next prime is 21201010221023. The reversal of 21201010221021 is 12012201010212.

It is a de Polignac number, because none of the positive numbers 2^k-21201010221021 is a prime.

It is a super-2 number, since 2×21201010221021² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201010221023) 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, 57271750 + ... + 57640743.

It is an arithmetic number, because the mean of its divisors is an integer number (1789187531580).

Almost surely, 2^{21201010221021} is an apocalyptic number.

It is an amenable number.

21201010221021 is a deficient number, since it is larger than the sum of its proper divisors (7425990284259).

21201010221021 is a wasteful number, since it uses less digits than its factorization.

21201010221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114913276.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21201010221021 its reverse (12012201010212), we get a palindrome (33213211231233).

The spelling of 21201010221021 in words is "twenty-one trillion, two hundred one billion, ten million, two hundred twenty-one thousand, twenty-one".