76785561 has 18 divisors (see below), whose sum is σ = 112522878. Its totient is φ = 50457600.

The previous prime is 76785559. The next prime is 76785581. The reversal of 76785561 is 16558767.

76785561 is a `hidden beast` number, since 7 + 6 + 7 + 85 + 561 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 41679936 + 35105625 = 6456^2 + 5925^2 .

It is not a de Polignac number, because 76785561 - 2¹ = 76785559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (76785581) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 47161 + ... + 48761.

It is an arithmetic number, because the mean of its divisors is an integer number (6251271).

Almost surely, 2^76785561 is an apocalyptic number.

It is an amenable number.

76785561 is a deficient number, since it is larger than the sum of its proper divisors (35737317).

76785561 is a wasteful number, since it uses less digits than its factorization.

76785561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1753 (or 1677 counting only the distinct ones).

The product of its digits is 352800, while the sum is 45.

The square root of 76785561 is about 8762.7370723992. The cubic root of 76785561 is about 425.0367875884.

The spelling of 76785561 in words is "seventy-six million, seven hundred eighty-five thousand, five hundred sixty-one".