1557297396 has 36 divisors (see below), whose sum is σ = 3938364612. Its totient is φ = 518853504.

The previous prime is 1557297373. The next prime is 1557297397. The reversal of 1557297396 is 6937927551.

It can be written as a sum of positive squares in 2 ways, for example, as 763748496 + 793548900 = 27636^2 + 28170^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1557297397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77110 + ... + 95186.

It is an arithmetic number, because the mean of its divisors is an integer number (109399017).

Almost surely, 2^1557297396 is an apocalyptic number.

It is an amenable number.

1557297396 is an abundant number, since it is smaller than the sum of its proper divisors (2381067216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1557297396 is a wasteful number, since it uses less digits than its factorization.

1557297396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20480 (or 20475 counting only the distinct ones).

The product of its digits is 3572100, while the sum is 54.

The square root of 1557297396 is about 39462.6075671641. The cubic root of 1557297396 is about 1159.1078643870.

The spelling of 1557297396 in words is "one billion, five hundred fifty-seven million, two hundred ninety-seven thousand, three hundred ninety-six".