1257818497 has 18 divisors (see below), whose sum is σ = 1381043538. Its totient is φ = 1144945152.

The previous prime is 1257818483. The next prime is 1257818533. The reversal of 1257818497 is 7948187521.

It can be written as a sum of positive squares in 9 ways, for example, as 1062825201 + 194993296 = 32601^2 + 13964^2 .

It is not a de Polignac number, because 1257818497 - 2⁷ = 1257818369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1257818417) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4540723 + ... + 4540999.

It is an arithmetic number, because the mean of its divisors is an integer number (76724641).

Almost surely, 2^1257818497 is an apocalyptic number.

It is an amenable number.

1257818497 is a deficient number, since it is larger than the sum of its proper divisors (123225041).

1257818497 is an frugal number, since it uses more digits than its factorization.

1257818497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 677 (or 387 counting only the distinct ones).

The product of its digits is 1128960, while the sum is 52.

The square root of 1257818497 is about 35465.7369442678. The cubic root of 1257818497 is about 1079.4586041049.

The spelling of 1257818497 in words is "one billion, two hundred fifty-seven million, eight hundred eighteen thousand, four hundred ninety-seven".