78642965 has 4 divisors (see below), whose sum is σ = 94371564. Its totient is φ = 62914368.

The previous prime is 78642959. The next prime is 78642997. The reversal of 78642965 is 56924687.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37246609 + 41396356 = 6103^2 + 6434^2 .

It is a cyclic number.

It is not a de Polignac number, because 78642965 - 2⁸ = 78642709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7864292 + ... + 7864301.

It is an arithmetic number, because the mean of its divisors is an integer number (23592891).

Almost surely, 2^78642965 is an apocalyptic number.

It is an amenable number.

78642965 is a deficient number, since it is larger than the sum of its proper divisors (15728599).

78642965 is a wasteful number, since it uses less digits than its factorization.

78642965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15728598.

The product of its digits is 725760, while the sum is 47.

The square root of 78642965 is about 8868.0868850051. The cubic root of 78642965 is about 428.4366613032.

The spelling of 78642965 in words is "seventy-eight million, six hundred forty-two thousand, nine hundred sixty-five".