78678994 has 4 divisors (see below), whose sum is σ = 118018494. Its totient is φ = 39339496.

The previous prime is 78678989. The next prime is 78679033. The reversal of 78678994 is 49987687.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 77668969 + 1010025 = 8813^2 + 1005^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19669747 + ... + 19669750.

Almost surely, 2^78678994 is an apocalyptic number.

78678994 is a deficient number, since it is larger than the sum of its proper divisors (39339500).

78678994 is a wasteful number, since it uses less digits than its factorization.

78678994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39339499.

The product of its digits is 6096384, while the sum is 58.

The square root of 78678994 is about 8870.1180375461. The cubic root of 78678994 is about 428.5020784188.

It can be divided in two parts, 7867 and 8994, that added together give a palindrome (16861).

The spelling of 78678994 in words is "seventy-eight million, six hundred seventy-eight thousand, nine hundred ninety-four".