21011201220021 has 32 divisors (see below), whose sum is σ = 29473295884032. Its totient is φ = 13288697326080.

The previous prime is 21011201220017. The next prime is 21011201220049. The reversal of 21011201220021 is 12002210211012.

It is not a de Polignac number, because 21011201220021 - 2² = 21011201220017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011201270021) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2403201 + ... + 6913593.

It is an arithmetic number, because the mean of its divisors is an integer number (921040496376).

Almost surely, 2^{21011201220021} is an apocalyptic number.

It is an amenable number.

21011201220021 is a deficient number, since it is larger than the sum of its proper divisors (8462094664011).

21011201220021 is a wasteful number, since it uses less digits than its factorization.

21011201220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4510973.

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

Adding to 21011201220021 its reverse (12002210211012), we get a palindrome (33013411431033).

The spelling of 21011201220021 in words is "twenty-one trillion, eleven billion, two hundred one million, two hundred twenty thousand, twenty-one".