78877565 has 16 divisors (see below), whose sum is σ = 102286128. Its totient is φ = 58046976.

The previous prime is 78877549. The next prime is 78877567. The reversal of 78877565 is 56577887.

It can be written as a sum of positive squares in 8 ways, for example, as 36445369 + 42432196 = 6037^2 + 6514^2 .

It is not a de Polignac number, because 78877565 - 2⁴ = 78877549 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 (78877567) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18407 + ... + 22283.

It is an arithmetic number, because the mean of its divisors is an integer number (6392883).

Almost surely, 2^78877565 is an apocalyptic number.

It is an amenable number.

78877565 is a deficient number, since it is larger than the sum of its proper divisors (23408563).

78877565 is a wasteful number, since it uses less digits than its factorization.

78877565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4208.

The product of its digits is 3292800, while the sum is 53.

The square root of 78877565 is about 8881.3042398062. The cubic root of 78877565 is about 428.8622618255.

The spelling of 78877565 in words is "seventy-eight million, eight hundred seventy-seven thousand, five hundred sixty-five".