21040031431 has 2 divisors, whose sum is σ = 21040031432. Its totient is φ = 21040031430.

The previous prime is 21040031429. The next prime is 21040031447. The reversal of 21040031431 is 13413004012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21040031431 - 2¹ = 21040031429 is a prime.

It is a super-2 number, since 2×21040031431² (a number of 21 digits) contains 22 as substring.

Together with 21040031429, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21040031399 and 21040031408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21040031461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10520015715 + 10520015716.

It is an arithmetic number, because the mean of its divisors is an integer number (10520015716).

Almost surely, 2^21040031431 is an apocalyptic number.

21040031431 is a deficient number, since it is larger than the sum of its proper divisors (1).

21040031431 is an equidigital number, since it uses as much as digits as its factorization.

21040031431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21040031431 its reverse (13413004012), we get a palindrome (34453035443).

The spelling of 21040031431 in words is "twenty-one billion, forty million, thirty-one thousand, four hundred thirty-one".