1264644257 has 2 divisors, whose sum is σ = 1264644258. Its totient is φ = 1264644256.

The previous prime is 1264644203. The next prime is 1264644281. The reversal of 1264644257 is 7524464621.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1264584721 + 59536 = 35561^2 + 244^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1264644257 is a prime.

It is not a weakly prime, because it can be changed into another prime (1264644757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632322128 + 632322129.

It is an arithmetic number, because the mean of its divisors is an integer number (632322129).

Almost surely, 2^1264644257 is an apocalyptic number.

It is an amenable number.

1264644257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1264644257 is an equidigital number, since it uses as much as digits as its factorization.

1264644257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 322560, while the sum is 41.

The square root of 1264644257 is about 35561.8370869673. The cubic root of 1264644257 is about 1081.4077028287.

The spelling of 1264644257 in words is "one billion, two hundred sixty-four million, six hundred forty-four thousand, two hundred fifty-seven".