71612981257 has 2 divisors, whose sum is σ = 71612981258. Its totient is φ = 71612981256.

The previous prime is 71612981243. The next prime is 71612981303. The reversal of 71612981257 is 75218921617.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70615621696 + 997359561 = 265736^2 + 31581^2 .

It is a cyclic number.

It is not a de Polignac number, because 71612981257 - 2¹¹ = 71612979209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71612981257.

It is not a weakly prime, because it can be changed into another prime (71612981057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35806490628 + 35806490629.

It is an arithmetic number, because the mean of its divisors is an integer number (35806490629).

Almost surely, 2^71612981257 is an apocalyptic number.

It is an amenable number.

71612981257 is a deficient number, since it is larger than the sum of its proper divisors (1).

71612981257 is an equidigital number, since it uses as much as digits as its factorization.

71612981257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 423360, while the sum is 49.

The spelling of 71612981257 in words is "seventy-one billion, six hundred twelve million, nine hundred eighty-one thousand, two hundred fifty-seven".