78564861 has 6 divisors (see below), whose sum is σ = 113482590. Its totient is φ = 52376568.

The previous prime is 78564853. The next prime is 78564877. The reversal of 78564861 is 16846587.

It is a happy number.

78564861 is a `hidden beast` number, since 7 + 8 + 564 + 86 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 66096900 + 12467961 = 8130^2 + 3531^2 .

It is not a de Polignac number, because 78564861 - 2³ = 78564853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78566861) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4364706 + ... + 4364723.

It is an arithmetic number, because the mean of its divisors is an integer number (18913765).

Almost surely, 2^78564861 is an apocalyptic number.

It is an amenable number.

78564861 is a deficient number, since it is larger than the sum of its proper divisors (34917729).

78564861 is a wasteful number, since it uses less digits than its factorization.

78564861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8729435 (or 8729432 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 78564861 is about 8863.6821355462. The cubic root of 78564861 is about 428.2947808401.

The spelling of 78564861 in words is "seventy-eight million, five hundred sixty-four thousand, eight hundred sixty-one".