21021000102 has 12 divisors (see below), whose sum is σ = 45545500260. Its totient is φ = 7007000028.

The previous prime is 21021000073. The next prime is 21021000103. The reversal of 21021000102 is 20100012012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021000103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 583916652 + ... + 583916687.

It is an arithmetic number, because the mean of its divisors is an integer number (3795458355).

Almost surely, 2^21021000102 is an apocalyptic number.

21021000102 is an abundant number, since it is smaller than the sum of its proper divisors (24524500158).

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

21021000102 is a wasteful number, since it uses less digits than its factorization.

21021000102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1167833347 (or 1167833344 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21021000102 its reverse (20100012012), we get a palindrome (41121012114).

The spelling of 21021000102 in words is "twenty-one billion, twenty-one million, one hundred two", and thus it is an aban number.