21103312020 has 48 divisors (see below), whose sum is σ = 67530599808. Its totient is φ = 4823614080.

The previous prime is 21103311979. The next prime is 21103312039. The reversal of 21103312020 is 2021330112.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

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, 25122571 + ... + 25123410.

It is an arithmetic number, because the mean of its divisors is an integer number (1406887496).

Almost surely, 2^21103312020 is an apocalyptic number.

21103312020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21103312020 is an abundant number, since it is smaller than the sum of its proper divisors (46427287788).

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

21103312020 is a wasteful number, since it uses less digits than its factorization.

21103312020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50246000 (or 50245998 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21103312020 its reverse (2021330112), we get a palindrome (23124642132).

The spelling of 21103312020 in words is "twenty-one billion, one hundred three million, three hundred twelve thousand, twenty".