31311243421 has 4 divisors (see below), whose sum is σ = 32390941500. Its totient is φ = 30231545344.

The previous prime is 31311243391. The next prime is 31311243449. The reversal of 31311243421 is 12434211313.

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

It can be written as a sum of positive squares in 2 ways, for example, as 26766596025 + 4544647396 = 163605^2 + 67414^2 .

It is a cyclic number.

It is not a de Polignac number, because 31311243421 - 2⁵ = 31311243389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31311243461) 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, 539848996 + ... + 539849053.

It is an arithmetic number, because the mean of its divisors is an integer number (8097735375).

Almost surely, 2^31311243421 is an apocalyptic number.

It is an amenable number.

31311243421 is a deficient number, since it is larger than the sum of its proper divisors (1079698079).

31311243421 is a wasteful number, since it uses less digits than its factorization.

31311243421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1079698078.

The product of its digits is 1728, while the sum is 25.

Adding to 31311243421 its reverse (12434211313), we get a palindrome (43745454734).

The spelling of 31311243421 in words is "thirty-one billion, three hundred eleven million, two hundred forty-three thousand, four hundred twenty-one".