21000102131221 has 32 divisors (see below), whose sum is σ = 21594967764480. Its totient is φ = 20412018579456.

The previous prime is 21000102131213. The next prime is 21000102131249. The reversal of 21000102131221 is 12213120100012.

It is not a de Polignac number, because 21000102131221 - 2³ = 21000102131213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000102131195 and 21000102131204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000102131621) 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, 5774015815 + ... + 5774019451.

It is an arithmetic number, because the mean of its divisors is an integer number (674842742640).

Almost surely, 2^{21000102131221} is an apocalyptic number.

It is an amenable number.

21000102131221 is a deficient number, since it is larger than the sum of its proper divisors (594865633259).

21000102131221 is a wasteful number, since it uses less digits than its factorization.

21000102131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5293.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21000102131221 its reverse (12213120100012), we get a palindrome (33213222231233).

The spelling of 21000102131221 in words is "twenty-one trillion, one hundred two million, one hundred thirty-one thousand, two hundred twenty-one".