21112102020 has 48 divisors (see below), whose sum is σ = 60371635968. Its totient is φ = 5510108160.

The previous prime is 21112102007. The next prime is 21112102027. The reversal of 21112102020 is 2020121112.

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 = 21112101987 and 21112102005.

It is not an unprimeable number, because it can be changed into a prime (21112102027) 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, 3740461 + ... + 3746100.

It is an arithmetic number, because the mean of its divisors is an integer number (1257742416).

Almost surely, 2^21112102020 is an apocalyptic number.

21112102020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112102020 is an abundant number, since it is smaller than the sum of its proper divisors (39259533948).

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

21112102020 is a wasteful number, since it uses less digits than its factorization.

21112102020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7486620 (or 7486618 counting only the distinct ones).

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

Adding to 21112102020 its reverse (2020121112), we get a palindrome (23132223132).

The spelling of 21112102020 in words is "twenty-one billion, one hundred twelve million, one hundred two thousand, twenty".