1257134742761 has 2 divisors, whose sum is σ = 1257134742762. Its totient is φ = 1257134742760.

The previous prime is 1257134742733. The next prime is 1257134742803. The reversal of 1257134742761 is 1672474317521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1246985389225 + 10149353536 = 1116685^2 + 100744^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1257134742761 is a prime.

It is a super-2 number, since 2×1257134742761² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1257134762761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628567371380 + 628567371381.

It is an arithmetic number, because the mean of its divisors is an integer number (628567371381).

Almost surely, 2^{1257134742761} is an apocalyptic number.

It is an amenable number.

1257134742761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1257134742761 is an equidigital number, since it uses as much as digits as its factorization.

1257134742761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1975680, while the sum is 50.

The spelling of 1257134742761 in words is "one trillion, two hundred fifty-seven billion, one hundred thirty-four million, seven hundred forty-two thousand, seven hundred sixty-one".