21012002102100 has 72 divisors (see below), whose sum is σ = 60804732136960. Its totient is φ = 5602278343680.

The previous prime is 21012002102099. The next prime is 21012002102129. The reversal of 21012002102100 is 120120021012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3937117 + ... + 7584516.

Almost surely, 2^{21012002102100} is an apocalyptic number.

21012002102100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012002102100 is an abundant number, since it is smaller than the sum of its proper divisors (39792730034860).

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

21012002102100 is a wasteful number, since it uses less digits than its factorization.

21012002102100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11527729 (or 11527722 counting only the distinct ones).

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

Adding to 21012002102100 its reverse (120120021012), we get a palindrome (21132122123112).

The spelling of 21012002102100 in words is "twenty-one trillion, twelve billion, two million, one hundred two thousand, one hundred".