1557799920 has 240 divisors, whose sum is σ = 5418215712. Its totient is φ = 400834560.

The previous prime is 1557799909. The next prime is 1557799963. The reversal of 1557799920 is 299977551.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3335527 + ... + 3335993.

Almost surely, 2^1557799920 is an apocalyptic number.

1557799920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1557799920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2709107856).

1557799920 is an abundant number, since it is smaller than the sum of its proper divisors (3860415792).

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

1557799920 is a wasteful number, since it uses less digits than its factorization.

1557799920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640 (or 631 counting only the distinct ones).

The product of its (nonzero) digits is 1786050, while the sum is 54.

The square root of 1557799920 is about 39468.9741442567. The cubic root of 1557799920 is about 1159.2325284106.

The spelling of 1557799920 in words is "one billion, five hundred fifty-seven million, seven hundred ninety-nine thousand, nine hundred twenty".