21323510020 has 24 divisors (see below), whose sum is σ = 44792962200. Its totient is φ = 8526815232.

The previous prime is 21323510011. The next prime is 21323510029. The reversal of 21323510020 is 2001532312.

It is an interprime number because it is at equal distance from previous prime (21323510011) and next prime (21323510029).

It can be written as a sum of positive squares in 4 ways, for example, as 26193924 + 21297316096 = 5118^2 + 145936^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21323510020.

It is not an unprimeable number, because it can be changed into a prime (21323510029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 93555 + ... + 226714.

It is an arithmetic number, because the mean of its divisors is an integer number (1866373425).

Almost surely, 2^21323510020 is an apocalyptic number.

21323510020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21323510020 is an abundant number, since it is smaller than the sum of its proper divisors (23469452180).

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

21323510020 is a wasteful number, since it uses less digits than its factorization.

21323510020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323607 (or 323605 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 19.

The spelling of 21323510020 in words is "twenty-one billion, three hundred twenty-three million, five hundred ten thousand, twenty".