31431709493 has 2 divisors, whose sum is σ = 31431709494. Its totient is φ = 31431709492.

The previous prime is 31431709489. The next prime is 31431709549. The reversal of 31431709493 is 39490713413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31369014769 + 62694724 = 177113^2 + 7918^2 .

It is a cyclic number.

It is not a de Polignac number, because 31431709493 - 2² = 31431709489 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31431709423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15715854746 + 15715854747.

It is an arithmetic number, because the mean of its divisors is an integer number (15715854747).

Almost surely, 2^31431709493 is an apocalyptic number.

It is an amenable number.

31431709493 is a deficient number, since it is larger than the sum of its proper divisors (1).

31431709493 is an equidigital number, since it uses as much as digits as its factorization.

31431709493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 244944, while the sum is 44.

The spelling of 31431709493 in words is "thirty-one billion, four hundred thirty-one million, seven hundred nine thousand, four hundred ninety-three".