21102100102020 has 48 divisors (see below), whose sum is σ = 67526720327808. Its totient is φ = 4823337166080.

The previous prime is 21102100102007. The next prime is 21102100102037. The reversal of 21102100102020 is 2020100120112.

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

It is a junction number, because it is equal to n+sod(n) for n = 21102100101987 and 21102100102005.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25121547321 + ... + 25121548160.

It is an arithmetic number, because the mean of its divisors is an integer number (1406806673496).

Almost surely, 2^{21102100102020} is an apocalyptic number.

21102100102020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102100102020 is an abundant number, since it is smaller than the sum of its proper divisors (46424620225788).

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

21102100102020 is a wasteful number, since it uses less digits than its factorization.

21102100102020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50243095500 (or 50243095498 counting only the distinct ones).

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

Adding to 21102100102020 its reverse (2020100120112), we get a palindrome (23122200222132).

The spelling of 21102100102020 in words is "twenty-one trillion, one hundred two billion, one hundred million, one hundred two thousand, twenty".