21312040431 has 16 divisors (see below), whose sum is σ = 31049930880. Its totient is φ = 12895305120.

The previous prime is 21312040411. The next prime is 21312040447. The reversal of 21312040431 is 13404021312.

It is not a de Polignac number, because 21312040431 - 2¹¹ = 21312038383 is a prime.

It is a super-2 number, since 2×21312040431² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21312040398 and 21312040407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312040411) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 506541 + ... + 546998.

It is an arithmetic number, because the mean of its divisors is an integer number (1940620680).

Almost surely, 2^21312040431 is an apocalyptic number.

21312040431 is a deficient number, since it is larger than the sum of its proper divisors (9737890449).

21312040431 is a wasteful number, since it uses less digits than its factorization.

21312040431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1054166.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21312040431 its reverse (13404021312), we get a palindrome (34716061743).

The spelling of 21312040431 in words is "twenty-one billion, three hundred twelve million, forty thousand, four hundred thirty-one".