21121202101021 has 16 divisors (see below), whose sum is σ = 24119922660480. Its totient is φ = 18307584472320.

The previous prime is 21121202101009. The next prime is 21121202101049. The reversal of 21121202101021 is 12010120212112.

It is not a de Polignac number, because 21121202101021 - 2⁵ = 21121202100989 is a prime.

It is a super-2 number, since 2×21121202101021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21121202100986 and 21121202101004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121202104021) 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, 133280256 + ... + 133438633.

It is an arithmetic number, because the mean of its divisors is an integer number (1507495166280).

Almost surely, 2^{21121202101021} is an apocalyptic number.

It is an amenable number.

21121202101021 is a deficient number, since it is larger than the sum of its proper divisors (2998720559459).

21121202101021 is a wasteful number, since it uses less digits than its factorization.

21121202101021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266719236.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21121202101021 its reverse (12010120212112), we get a palindrome (33131322313133).

The spelling of 21121202101021 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred two million, one hundred one thousand, twenty-one".