1557944397 has 12 divisors (see below), whose sum is σ = 2250770080. Its totient is φ = 1038442248.

The previous prime is 1557944389. The next prime is 1557944417. The reversal of 1557944397 is 7934497551.

It is not a de Polignac number, because 1557944397 - 2³ = 1557944389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1557944327) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52854 + ... + 76872.

Almost surely, 2^1557944397 is an apocalyptic number.

It is an amenable number.

1557944397 is a deficient number, since it is larger than the sum of its proper divisors (692825683).

1557944397 is a wasteful number, since it uses less digits than its factorization.

1557944397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31232 (or 31229 counting only the distinct ones).

The product of its digits is 4762800, while the sum is 54.

The square root of 1557944397 is about 39470.8043622118. The cubic root of 1557944397 is about 1159.2683646903.

The spelling of 1557944397 in words is "one billion, five hundred fifty-seven million, nine hundred forty-four thousand, three hundred ninety-seven".