21001020021102 has 16 divisors (see below), whose sum is σ = 45820407318912. Its totient is φ = 6363945460920.

The previous prime is 21001020021029. The next prime is 21001020021103. The reversal of 21001020021102 is 20112002010012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001020021103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 159098636458 + ... + 159098636589.

It is an arithmetic number, because the mean of its divisors is an integer number (2863775457432).

Almost surely, 2^{21001020021102} is an apocalyptic number.

21001020021102 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21001020021102 is an abundant number, since it is smaller than the sum of its proper divisors (24819387297810).

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

21001020021102 is a wasteful number, since it uses less digits than its factorization.

21001020021102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318197273063.

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

Adding to 21001020021102 its reverse (20112002010012), we get a palindrome (41113022031114).

The spelling of 21001020021102 in words is "twenty-one trillion, one billion, twenty million, twenty-one thousand, one hundred two".