1656557568 has 130 divisors (see below), whose sum is σ = 4949608334. Its totient is φ = 552075264.

The previous prime is 1656557519. The next prime is 1656557569. The reversal of 1656557568 is 8657556561.

1656557568 is a `hidden beast` number, since 1 + 6 + 5 + 6 + 5 + 575 + 68 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1316818944 + 339738624 = 36288^2 + 18432^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (1656557569) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 329280 + ... + 334272.

Almost surely, 2^1656557568 is an apocalyptic number.

1656557568 is a gapful number since it is divisible by the number (18) 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 1656557568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2474804167).

1656557568 is an abundant number, since it is smaller than the sum of its proper divisors (3293050766).

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

1656557568 is an frugal number, since it uses more digits than its factorization.

1656557568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5029 (or 4998 counting only the distinct ones).

The product of its digits is 7560000, while the sum is 54.

The square root of 1656557568 is about 40700.8300652456. The cubic root of 1656557568 is about 1183.2291061719.

The spelling of 1656557568 in words is "one billion, six hundred fifty-six million, five hundred fifty-seven thousand, five hundred sixty-eight".