78939998 has 4 divisors (see below), whose sum is σ = 118410000. Its totient is φ = 39469998.

The previous prime is 78939989. The next prime is 78940007. The reversal of 78939998 is 89993987.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 89993987 = 131 ⋅686977.

It is an interprime number because it is at equal distance from previous prime (78939989) and next prime (78940007).

It is a self number, because there is not a number n which added to its sum of digits gives 78939998.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19734998 + ... + 19735001.

It is an arithmetic number, because the mean of its divisors is an integer number (29602500).

Almost surely, 2^78939998 is an apocalyptic number.

78939998 is a deficient number, since it is larger than the sum of its proper divisors (39470002).

78939998 is a wasteful number, since it uses less digits than its factorization.

78939998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39470001.

The product of its digits is 8817984, while the sum is 62.

The square root of 78939998 is about 8884.8183999449. The cubic root of 78939998 is about 428.9753826957.

The spelling of 78939998 in words is "seventy-eight million, nine hundred thirty-nine thousand, nine hundred ninety-eight".