1557233640 has 64 divisors (see below), whose sum is σ = 5190782400. Its totient is φ = 415262016.

The previous prime is 1557233627. The next prime is 1557233641. The reversal of 1557233640 is 463327551.

1557233640 is a `hidden beast` number, since 1 + 5 + 5 + 7 + 2 + 3 + 3 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1557233595 and 1557233604.

It is not an unprimeable number, because it can be changed into a prime (1557233641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 719862 + ... + 722021.

It is an arithmetic number, because the mean of its divisors is an integer number (81105975).

Almost surely, 2^1557233640 is an apocalyptic number.

1557233640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1557233640 is an abundant number, since it is smaller than the sum of its proper divisors (3633548760).

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

1557233640 is a wasteful number, since it uses less digits than its factorization.

1557233640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1441903 (or 1441893 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 36.

The square root of 1557233640 is about 39461.7997562199. The cubic root of 1557233640 is about 1159.0920461518.

The spelling of 1557233640 in words is "one billion, five hundred fifty-seven million, two hundred thirty-three thousand, six hundred forty".