1257660705 has 24 divisors (see below), whose sum is σ = 2340790272. Its totient is φ = 574930272.

The previous prime is 1257660671. The next prime is 1257660707. The reversal of 1257660705 is 5070667521.

It is not a de Polignac number, because 1257660705 - 2⁷ = 1257660577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1257660707) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 854817 + ... + 856286.

It is an arithmetic number, because the mean of its divisors is an integer number (97532928).

Almost surely, 2^1257660705 is an apocalyptic number.

1257660705 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1257660705 is a deficient number, since it is larger than the sum of its proper divisors (1083129567).

1257660705 is a wasteful number, since it uses less digits than its factorization.

1257660705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1711125 (or 1711118 counting only the distinct ones).

The product of its (nonzero) digits is 88200, while the sum is 39.

The square root of 1257660705 is about 35463.5123049029. The cubic root of 1257660705 is about 1079.4134632372.

The spelling of 1257660705 in words is "one billion, two hundred fifty-seven million, six hundred sixty thousand, seven hundred five".