21300300021 has 32 divisors (see below), whose sum is σ = 38132011008. Its totient is φ = 10213928640.

The previous prime is 21300300017. The next prime is 21300300061. The reversal of 21300300021 is 12000300312.

It is a happy number.

It is not a de Polignac number, because 21300300021 - 2² = 21300300017 is a prime.

It is a super-2 number, since 2×21300300021² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300300061) 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 31 ways as a sum of consecutive naturals, for example, 3543501 + ... + 3549506.

It is an arithmetic number, because the mean of its divisors is an integer number (1191625344).

Almost surely, 2^21300300021 is an apocalyptic number.

21300300021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21300300021 is a deficient number, since it is larger than the sum of its proper divisors (16831710987).

21300300021 is a wasteful number, since it uses less digits than its factorization.

21300300021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7093041.

The product of its (nonzero) digits is 36, while the sum is 12.

Adding to 21300300021 its reverse (12000300312), we get a palindrome (33300600333).

The spelling of 21300300021 in words is "twenty-one billion, three hundred million, three hundred thousand, twenty-one".