20101221012021 has 32 divisors (see below), whose sum is σ = 28724728249728. Its totient is φ = 12458564751360.

The previous prime is 20101221012013. The next prime is 20101221012071. The reversal of 20101221012021 is 12021012210102.

It is not a de Polignac number, because 20101221012021 - 2³ = 20101221012013 is a prime.

It is a super-2 number, since 2×20101221012021² (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 (20101221012071) 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, 26106411 + ... + 26865351.

It is an arithmetic number, because the mean of its divisors is an integer number (897647757804).

Almost surely, 2^{20101221012021} is an apocalyptic number.

It is an amenable number.

20101221012021 is a deficient number, since it is larger than the sum of its proper divisors (8623507237707).

20101221012021 is a wasteful number, since it uses less digits than its factorization.

20101221012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765301.

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

Adding to 20101221012021 its reverse (12021012210102), we get a palindrome (32122233222123).

The spelling of 20101221012021 in words is "twenty trillion, one hundred one billion, two hundred twenty-one million, twelve thousand, twenty-one".