21300431525 has 12 divisors (see below), whose sum is σ = 26440279812. Its totient is φ = 17022445440.

The previous prime is 21300431489. The next prime is 21300431549. The reversal of 21300431525 is 52513400312.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 8076964 + 21292354561 = 2842^2 + 145919^2 .

It is not a de Polignac number, because 21300431525 - 2³⁰ = 20226689701 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21300431494 and 21300431503.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 423194 + ... + 470843.

It is an arithmetic number, because the mean of its divisors is an integer number (2203356651).

Almost surely, 2^21300431525 is an apocalyptic number.

21300431525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21300431525 is a deficient number, since it is larger than the sum of its proper divisors (5139848287).

21300431525 is an equidigital number, since it uses as much as digits as its factorization.

21300431525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895000 (or 894995 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21300431525 its reverse (52513400312), we get a palindrome (73813831837).

The spelling of 21300431525 in words is "twenty-one billion, three hundred million, four hundred thirty-one thousand, five hundred twenty-five".