1251061657 has 2 divisors, whose sum is σ = 1251061658. Its totient is φ = 1251061656.

The previous prime is 1251061639. The next prime is 1251061667. The reversal of 1251061657 is 7561601521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 723394816 + 527666841 = 26896^2 + 22971^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1251061657 is a prime.

It is not a weakly prime, because it can be changed into another prime (1251061667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625530828 + 625530829.

It is an arithmetic number, because the mean of its divisors is an integer number (625530829).

Almost surely, 2^1251061657 is an apocalyptic number.

It is an amenable number.

1251061657 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251061657 is an equidigital number, since it uses as much as digits as its factorization.

1251061657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12600, while the sum is 34.

The square root of 1251061657 is about 35370.3499699961. The cubic root of 1251061657 is about 1077.5222281398.

The spelling of 1251061657 in words is "one billion, two hundred fifty-one million, sixty-one thousand, six hundred fifty-seven".