31431709549 has 2 divisors, whose sum is σ = 31431709550. Its totient is φ = 31431709548.

The previous prime is 31431709493. The next prime is 31431709637. The reversal of 31431709549 is 94590713413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29360822500 + 2070887049 = 171350^2 + 45507^2 .

It is a cyclic number.

It is not a de Polignac number, because 31431709549 - 2²¹ = 31429612397 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31431709499 and 31431709508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31431709249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15715854774 + 15715854775.

It is an arithmetic number, because the mean of its divisors is an integer number (15715854775).

Almost surely, 2^31431709549 is an apocalyptic number.

It is an amenable number.

31431709549 is a deficient number, since it is larger than the sum of its proper divisors (1).

31431709549 is an equidigital number, since it uses as much as digits as its factorization.

31431709549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 408240, while the sum is 46.

The spelling of 31431709549 in words is "thirty-one billion, four hundred thirty-one million, seven hundred nine thousand, five hundred forty-nine".