78399387 has 48 divisors (see below), whose sum is σ = 132720000. Its totient is φ = 45357840.

The previous prime is 78399379. The next prime is 78399389.

78399387 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 78399387 - 2³ = 78399379 is a prime.

It is a super-2 number, since 2×78399387² = 12292927763951538, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78399389) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 156864 + ... + 157362.

It is an arithmetic number, because the mean of its divisors is an integer number (2765000).

Almost surely, 2^78399387 is an apocalyptic number.

78399387 is a deficient number, since it is larger than the sum of its proper divisors (54320613).

78399387 is a wasteful number, since it uses less digits than its factorization.

78399387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565 (or 536 counting only the distinct ones).

The product of its digits is 2286144, while the sum is 54.

The square root of 78399387 is about 8854.3428327573. The cubic root of 78399387 is about 427.9938767430.

The spelling of 78399387 in words is "seventy-eight million, three hundred ninety-nine thousand, three hundred eighty-seven".