31231321019 has 2 divisors, whose sum is σ = 31231321020. Its totient is φ = 31231321018.

The previous prime is 31231321007. The next prime is 31231321049. The reversal of 31231321019 is 91012313213.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31231321019 - 2¹⁶ = 31231255483 is a prime.

It is a super-2 number, since 2×31231321019² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31231321049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15615660509 + 15615660510.

It is an arithmetic number, because the mean of its divisors is an integer number (15615660510).

Almost surely, 2^31231321019 is an apocalyptic number.

31231321019 is a deficient number, since it is larger than the sum of its proper divisors (1).

31231321019 is an equidigital number, since it uses as much as digits as its factorization.

31231321019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972, while the sum is 26.

The spelling of 31231321019 in words is "thirty-one billion, two hundred thirty-one million, three hundred twenty-one thousand, nineteen".