21320412020 has 24 divisors (see below), whose sum is σ = 45125412864. Its totient is φ = 8461012896.

The previous prime is 21320412019. The next prime is 21320412049. The reversal of 21320412020 is 2021402312.

It is a self number, because there is not a number n which added to its sum of digits gives 21320412020.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4194392 + ... + 4199471.

It is an arithmetic number, because the mean of its divisors is an integer number (1880225536).

Almost surely, 2^21320412020 is an apocalyptic number.

21320412020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21320412020 is an abundant number, since it is smaller than the sum of its proper divisors (23805000844).

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

21320412020 is a wasteful number, since it uses less digits than its factorization.

21320412020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8393999 (or 8393997 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21320412020 its reverse (2021402312), we get a palindrome (23341814332).

The spelling of 21320412020 in words is "twenty-one billion, three hundred twenty million, four hundred twelve thousand, twenty".