1257131549 has 2 divisors, whose sum is σ = 1257131550. Its totient is φ = 1257131548.

The previous prime is 1257131509. The next prime is 1257131587. The reversal of 1257131549 is 9451317521.

It is an a-pointer prime, because the next prime (1257131587) can be obtained adding 1257131549 to its sum of digits (38).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 936972100 + 320159449 = 30610^2 + 17893^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1257131549 is a prime.

It is a super-2 number, since 2×1257131549² = 3160759462982278802, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1257131509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628565774 + 628565775.

It is an arithmetic number, because the mean of its divisors is an integer number (628565775).

Almost surely, 2^1257131549 is an apocalyptic number.

It is an amenable number.

1257131549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1257131549 is an equidigital number, since it uses as much as digits as its factorization.

1257131549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37800, while the sum is 38.

The square root of 1257131549 is about 35456.0509504372. The cubic root of 1257131549 is about 1079.2620556188.

The spelling of 1257131549 in words is "one billion, two hundred fifty-seven million, one hundred thirty-one thousand, five hundred forty-nine".