31445987257 has 2 divisors, whose sum is σ = 31445987258. Its totient is φ = 31445987256.

The previous prime is 31445987233. The next prime is 31445987299. The reversal of 31445987257 is 75278954413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31435644601 + 10342656 = 177301^2 + 3216^2 .

It is a cyclic number.

It is not a de Polignac number, because 31445987257 - 2¹⁵ = 31445954489 is a prime.

It is a super-2 number, since 2×31445987257² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31445987198 and 31445987207.

It is not a weakly prime, because it can be changed into another prime (31445987357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15722993628 + 15722993629.

It is an arithmetic number, because the mean of its divisors is an integer number (15722993629).

Almost surely, 2^31445987257 is an apocalyptic number.

It is an amenable number.

31445987257 is a deficient number, since it is larger than the sum of its proper divisors (1).

31445987257 is an equidigital number, since it uses as much as digits as its factorization.

31445987257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8467200, while the sum is 55.

The spelling of 31445987257 in words is "thirty-one billion, four hundred forty-five million, nine hundred eighty-seven thousand, two hundred fifty-seven".