21201300020 has 24 divisors (see below), whose sum is σ = 44648871624. Its totient is φ = 8456493056.

The previous prime is 21201300017. The next prime is 21201300023. The reversal of 21201300020 is 2000310212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21201300017) and next prime (21201300023).

It can be written as a sum of positive squares in 4 ways, for example, as 83978896 + 21117321124 = 9164^2 + 145318^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21201299974 and 21201300010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201300023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1494449 + ... + 1508568.

It is an arithmetic number, because the mean of its divisors is an integer number (1860369651).

Almost surely, 2^21201300020 is an apocalyptic number.

21201300020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201300020 is an abundant number, since it is smaller than the sum of its proper divisors (23447571604).

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

21201300020 is a wasteful number, since it uses less digits than its factorization.

21201300020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3003379 (or 3003377 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

Adding to 21201300020 its reverse (2000310212), we get a palindrome (23201610232).

The spelling of 21201300020 in words is "twenty-one billion, two hundred one million, three hundred thousand, twenty".