78265865 has 8 divisors (see below), whose sum is σ = 94323528. Its totient is φ = 62343040.

The previous prime is 78265861. The next prime is 78265871. The reversal of 78265865 is 56856287.

It can be written as a sum of positive squares in 4 ways, for example, as 19114384 + 59151481 = 4372^2 + 7691^2 .

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

It is not a de Polignac number, because 78265865 - 2² = 78265861 is a prime.

It is a super-2 number, since 2×78265865² = 12251091248396450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78265861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32426 + ... + 34755.

It is an arithmetic number, because the mean of its divisors is an integer number (11790441).

Almost surely, 2^78265865 is an apocalyptic number.

It is an amenable number.

78265865 is a deficient number, since it is larger than the sum of its proper divisors (16057663).

78265865 is a wasteful number, since it uses less digits than its factorization.

78265865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67419.

The product of its digits is 806400, while the sum is 47.

The square root of 78265865 is about 8846.7997038477. The cubic root of 78265865 is about 427.7507665459.

The spelling of 78265865 in words is "seventy-eight million, two hundred sixty-five thousand, eight hundred sixty-five".