1257347947 has 2 divisors, whose sum is σ = 1257347948. Its totient is φ = 1257347946.

The previous prime is 1257347909. The next prime is 1257347951. The reversal of 1257347947 is 7497437521.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1257347947 is a prime.

It is a super-2 number, since 2×1257347947² = 3161847719650229618, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1257347947.

It is not a weakly prime, because it can be changed into another prime (1257347957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628673973 + 628673974.

It is an arithmetic number, because the mean of its divisors is an integer number (628673974).

Almost surely, 2^1257347947 is an apocalyptic number.

1257347947 is a deficient number, since it is larger than the sum of its proper divisors (1).

1257347947 is an equidigital number, since it uses as much as digits as its factorization.

1257347947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1481760, while the sum is 49.

The square root of 1257347947 is about 35459.1024562100. The cubic root of 1257347947 is about 1079.3239787991.

The spelling of 1257347947 in words is "one billion, two hundred fifty-seven million, three hundred forty-seven thousand, nine hundred forty-seven".