1266257257 has 6 divisors (see below), whose sum is σ = 1345124798. Its totient is φ = 1191771264.

The previous prime is 1266257231. The next prime is 1266257263. The reversal of 1266257257 is 7527526621.

It can be written as a sum of positive squares in 3 ways, for example, as 611869696 + 654387561 = 24736^2 + 25581^2 .

It is not a de Polignac number, because 1266257257 - 2⁷ = 1266257129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1266257207) 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 in 5 ways as a sum of consecutive naturals, for example, 2190468 + ... + 2191045.

Almost surely, 2^1266257257 is an apocalyptic number.

1266257257 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1266257257 is a deficient number, since it is larger than the sum of its proper divisors (78867541).

1266257257 is an equidigital number, since it uses as much as digits as its factorization.

1266257257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4381547 (or 4381530 counting only the distinct ones).

The product of its digits is 352800, while the sum is 43.

The square root of 1266257257 is about 35584.5086659912. The cubic root of 1266257257 is about 1081.8672706853.

The spelling of 1266257257 in words is "one billion, two hundred sixty-six million, two hundred fifty-seven thousand, two hundred fifty-seven".