21300312431 has 4 divisors (see below), whose sum is σ = 21300650712. Its totient is φ = 21299974152.

The previous prime is 21300312419. The next prime is 21300312479. The reversal of 21300312431 is 13421300312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21300312431 is a prime.

It is a super-2 number, since 2×21300312431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300312331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43661 + ... + 210966.

It is an arithmetic number, because the mean of its divisors is an integer number (5325162678).

Almost surely, 2^21300312431 is an apocalyptic number.

21300312431 is a deficient number, since it is larger than the sum of its proper divisors (338281).

21300312431 is an equidigital number, since it uses as much as digits as its factorization.

21300312431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338280.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21300312431 its reverse (13421300312), we get a palindrome (34721612743).

The spelling of 21300312431 in words is "twenty-one billion, three hundred million, three hundred twelve thousand, four hundred thirty-one".