561664377 has 36 divisors (see below), whose sum is σ = 906696180. Its totient is φ = 333835776.

The previous prime is 561664361. The next prime is 561664379. The reversal of 561664377 is 773466165.

561664377 is a `hidden beast` number, since 56 + 166 + 437 + 7 = 666.

561664377 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 486599481 + 75064896 = 22059^2 + 8664^2 .

It is not a de Polignac number, because 561664377 - 2⁴ = 561664361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (561664379) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 50149 + ... + 60317.

It is an arithmetic number, because the mean of its divisors is an integer number (25186005).

Almost surely, 2^561664377 is an apocalyptic number.

561664377 is a gapful number since it is divisible by the number (57) formed by its first and last digit.

It is an amenable number.

561664377 is a deficient number, since it is larger than the sum of its proper divisors (345031803).

561664377 is a wasteful number, since it uses less digits than its factorization.

561664377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10230 (or 10208 counting only the distinct ones).

The product of its digits is 635040, while the sum is 45.

The square root of 561664377 is about 23699.4594242147. The cubic root of 561664377 is about 825.0728442567.

The spelling of 561664377 in words is "five hundred sixty-one million, six hundred sixty-four thousand, three hundred seventy-seven".