21221100201021 has 64 divisors (see below), whose sum is σ = 33301941184512. Its totient is φ = 11767754880000.

The previous prime is 21221100201019. The next prime is 21221100201023. The reversal of 21221100201021 is 12010200112212.

It is an interprime number because it is at equal distance from previous prime (21221100201019) and next prime (21221100201023).

It is not a de Polignac number, because 21221100201021 - 2¹ = 21221100201019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221100201023) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 138071506 + ... + 138225116.

It is an arithmetic number, because the mean of its divisors is an integer number (520342831008).

Almost surely, 2^{21221100201021} is an apocalyptic number.

21221100201021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21221100201021 is a deficient number, since it is larger than the sum of its proper divisors (12080840983491).

21221100201021 is a wasteful number, since it uses less digits than its factorization.

21221100201021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154514.

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

Adding to 21221100201021 its reverse (12010200112212), we get a palindrome (33231300313233).

The spelling of 21221100201021 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred million, two hundred one thousand, twenty-one".