78553865 has 8 divisors (see below), whose sum is σ = 101515848. Its totient is φ = 58008960.

The previous prime is 78553859. The next prime is 78553883. The reversal of 78553865 is 56835587.

It can be written as a sum of positive squares in 4 ways, for example, as 355216 + 78198649 = 596^2 + 8843^2 .

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

It is not a de Polignac number, because 78553865 - 2⁸ = 78553609 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 604196 + ... + 604325.

It is an arithmetic number, because the mean of its divisors is an integer number (12689481).

Almost surely, 2^78553865 is an apocalyptic number.

It is an amenable number.

78553865 is a deficient number, since it is larger than the sum of its proper divisors (22961983).

78553865 is a wasteful number, since it uses less digits than its factorization.

78553865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208539.

The product of its digits is 1008000, while the sum is 47.

The square root of 78553865 is about 8863.0618298644. The cubic root of 78553865 is about 428.2747984159.

The spelling of 78553865 in words is "seventy-eight million, five hundred fifty-three thousand, eight hundred sixty-five".