31343121421 has 2 divisors, whose sum is σ = 31343121422. Its totient is φ = 31343121420.

The previous prime is 31343121409. The next prime is 31343121437. The reversal of 31343121421 is 12412134313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27394884196 + 3948237225 = 165514^2 + 62835^2 .

It is a cyclic number.

It is not a de Polignac number, because 31343121421 - 2⁹ = 31343120909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31343121721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15671560710 + 15671560711.

It is an arithmetic number, because the mean of its divisors is an integer number (15671560711).

Almost surely, 2^31343121421 is an apocalyptic number.

It is an amenable number.

31343121421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31343121421 is an equidigital number, since it uses as much as digits as its factorization.

31343121421 is an evil number, because the sum of its binary digits is even.

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

Adding to 31343121421 its reverse (12412134313), we get a palindrome (43755255734).

The spelling of 31343121421 in words is "thirty-one billion, three hundred forty-three million, one hundred twenty-one thousand, four hundred twenty-one".