1257665507 has 12 divisors (see below), whose sum is σ = 1526608656. Its totient is φ = 1031128560.

The previous prime is 1257665501. The next prime is 1257665569. The reversal of 1257665507 is 7055667521.

It is not a de Polignac number, because 1257665507 - 2⁸ = 1257665251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1257665501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 556844 + ... + 559097.

It is an arithmetic number, because the mean of its divisors is an integer number (127217388).

Almost surely, 2^1257665507 is an apocalyptic number.

1257665507 is a deficient number, since it is larger than the sum of its proper divisors (268943149).

1257665507 is a wasteful number, since it uses less digits than its factorization.

1257665507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1115978 (or 1115971 counting only the distinct ones).

The product of its (nonzero) digits is 441000, while the sum is 44.

The square root of 1257665507 is about 35463.5800082282. The cubic root of 1257665507 is about 1079.4148370409.

The spelling of 1257665507 in words is "one billion, two hundred fifty-seven million, six hundred sixty-five thousand, five hundred seven".