78645889 has 4 divisors (see below), whose sum is σ = 89881024. Its totient is φ = 67410756.

The previous prime is 78645887. The next prime is 78645937. The reversal of 78645889 is 98854687.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 78645889 - 2¹ = 78645887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78645887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5617557 + ... + 5617570.

It is an arithmetic number, because the mean of its divisors is an integer number (22470256).

Almost surely, 2^78645889 is an apocalyptic number.

It is an amenable number.

78645889 is a deficient number, since it is larger than the sum of its proper divisors (11235135).

78645889 is a wasteful number, since it uses less digits than its factorization.

78645889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11235134.

The product of its digits is 3870720, while the sum is 55.

The square root of 78645889 is about 8868.2517442842. The cubic root of 78645889 is about 428.4419710948.

The spelling of 78645889 in words is "seventy-eight million, six hundred forty-five thousand, eight hundred eighty-nine".