31541357857 has 2 divisors, whose sum is σ = 31541357858. Its totient is φ = 31541357856.

The previous prime is 31541357849. The next prime is 31541357863. The reversal of 31541357857 is 75875314513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20380703121 + 11160654736 = 142761^2 + 105644^2 .

It is an emirp because it is prime and its reverse (75875314513) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31541357857 - 2³ = 31541357849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31541357857.

It is not a weakly prime, because it can be changed into another prime (31541307857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15770678928 + 15770678929.

It is an arithmetic number, because the mean of its divisors is an integer number (15770678929).

Almost surely, 2^31541357857 is an apocalyptic number.

It is an amenable number.

31541357857 is a deficient number, since it is larger than the sum of its proper divisors (1).

31541357857 is an equidigital number, since it uses as much as digits as its factorization.

31541357857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1764000, while the sum is 49.

The spelling of 31541357857 in words is "thirty-one billion, five hundred forty-one million, three hundred fifty-seven thousand, eight hundred fifty-seven".