1297400857 has 2 divisors, whose sum is σ = 1297400858. Its totient is φ = 1297400856.

The previous prime is 1297400851. The next prime is 1297400873. The reversal of 1297400857 is 7580047921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1291755481 + 5645376 = 35941^2 + 2376^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1297400857 is a prime.

It is not a weakly prime, because it can be changed into another prime (1297400851) 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, 648700428 + 648700429.

It is an arithmetic number, because the mean of its divisors is an integer number (648700429).

Almost surely, 2^1297400857 is an apocalyptic number.

It is an amenable number.

1297400857 is a deficient number, since it is larger than the sum of its proper divisors (1).

1297400857 is an equidigital number, since it uses as much as digits as its factorization.

1297400857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 141120, while the sum is 43.

The square root of 1297400857 is about 36019.4510924306. The cubic root of 1297400857 is about 1090.6650423494.

The spelling of 1297400857 in words is "one billion, two hundred ninety-seven million, four hundred thousand, eight hundred fifty-seven".