1397793257 has 8 divisors (see below), whose sum is σ = 1630080000. Its totient is φ = 1198108212.

The previous prime is 1397793233. The next prime is 1397793277. The reversal of 1397793257 is 7523977931.

It is a de Polignac number, because none of the positive numbers 2^k-1397793257 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1397793199 and 1397793208.

It is not an unprimeable number, because it can be changed into a prime (1397793277) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2037257 + ... + 2037942.

It is an arithmetic number, because the mean of its divisors is an integer number (203760000).

Almost surely, 2^1397793257 is an apocalyptic number.

It is an amenable number.

1397793257 is a deficient number, since it is larger than the sum of its proper divisors (232286743).

1397793257 is an frugal number, since it uses more digits than its factorization.

1397793257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4075220 (or 4075206 counting only the distinct ones).

The product of its digits is 2500470, while the sum is 53.

The square root of 1397793257 is about 37387.0733944234. The cubic root of 1397793257 is about 1118.1008570339.

The spelling of 1397793257 in words is "one billion, three hundred ninety-seven million, seven hundred ninety-three thousand, two hundred fifty-seven".