1257696157 has 6 divisors (see below), whose sum is σ = 1302561338. Its totient is φ = 1214326512.

The previous prime is 1257696151. The next prime is 1257696191. The reversal of 1257696157 is 7516967521.

It can be written as a sum of positive squares in 3 ways, for example, as 29474041 + 1228222116 = 5429^2 + 35046^2 .

It is not a de Polignac number, because 1257696157 - 2³ = 1257696149 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1257696157.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1257696151) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 746898 + ... + 748579.

Almost surely, 2^1257696157 is an apocalyptic number.

It is an amenable number.

1257696157 is a deficient number, since it is larger than the sum of its proper divisors (44865181).

1257696157 is an equidigital number, since it uses as much as digits as its factorization.

1257696157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1495535 (or 1495506 counting only the distinct ones).

The product of its digits is 793800, while the sum is 49.

The square root of 1257696157 is about 35464.0121390685. The cubic root of 1257696157 is about 1079.4236056141.

The spelling of 1257696157 in words is "one billion, two hundred fifty-seven million, six hundred ninety-six thousand, one hundred fifty-seven".