21021012102 has 32 divisors (see below), whose sum is σ = 44350456320. Its totient is φ = 6623860320.

The previous prime is 21021012041. The next prime is 21021012109. The reversal of 21021012102 is 20121012012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021012109) 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, 146349 + ... + 251912.

It is an arithmetic number, because the mean of its divisors is an integer number (1385951760).

Almost surely, 2^21021012102 is an apocalyptic number.

21021012102 is an abundant number, since it is smaller than the sum of its proper divisors (23329444218).

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

21021012102 is a wasteful number, since it uses less digits than its factorization.

21021012102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398748.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21021012102 its reverse (20121012012), we get a palindrome (41142024114).

The spelling of 21021012102 in words is "twenty-one billion, twenty-one million, twelve thousand, one hundred two".