5656561999 has 8 divisors (see below), whose sum is σ = 6186343248. Its totient is φ = 5129372160.

The previous prime is 5656561993. The next prime is 5656562011. The reversal of 5656561999 is 9991656565.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 5656561999 - 2¹⁵ = 5656529231 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 (5656561993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 643282 + ... + 652015.

It is an arithmetic number, because the mean of its divisors is an integer number (773292906).

Almost surely, 2^5656561999 is an apocalyptic number.

5656561999 is a deficient number, since it is larger than the sum of its proper divisors (529781249).

5656561999 is a wasteful number, since it uses less digits than its factorization.

5656561999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1295705.

The product of its digits is 19683000, while the sum is 61.

The square root of 5656561999 is about 75210.1189933908. The cubic root of 5656561999 is about 1781.7667513733.

The spelling of 5656561999 in words is "five billion, six hundred fifty-six million, five hundred sixty-one thousand, nine hundred ninety-nine".