21000102131220 has 96 divisors (see below), whose sum is σ = 59426253887616. Its totient is φ = 5540449689600.

The previous prime is 21000102131213. The next prime is 21000102131249. The reversal of 21000102131220 is 2213120100012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21000102131220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16924840 + ... + 18123200.

It is an arithmetic number, because the mean of its divisors is an integer number (619023477996).

Almost surely, 2^{21000102131220} is an apocalyptic number.

21000102131220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21000102131220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29713126943808).

21000102131220 is an abundant number, since it is smaller than the sum of its proper divisors (38426151756396).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21000102131220 is a wasteful number, since it uses less digits than its factorization.

21000102131220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1201481 (or 1201479 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21000102131220 its reverse (2213120100012), we get a palindrome (23213222231232).

The spelling of 21000102131220 in words is "twenty-one trillion, one hundred two million, one hundred thirty-one thousand, two hundred twenty".