78739999 has 8 divisors (see below), whose sum is σ = 85307040. Its totient is φ = 72245856.

The previous prime is 78739987. The next prime is 78740021. The reversal of 78739999 is 99993787.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78739999 - 2⁹ = 78739487 is a prime.

78739999 is a modest number, since divided by 9999 gives 7873 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78739919) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15964 + ... + 20305.

It is an arithmetic number, because the mean of its divisors is an integer number (10663380).

Almost surely, 2^78739999 is an apocalyptic number.

78739999 is a deficient number, since it is larger than the sum of its proper divisors (6567041).

78739999 is a wasteful number, since it uses less digits than its factorization.

78739999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36449.

The product of its digits is 7715736, while the sum is 61.

The square root of 78739999 is about 8873.5561642444. The cubic root of 78739999 is about 428.6127984244.

The spelling of 78739999 in words is "seventy-eight million, seven hundred thirty-nine thousand, nine hundred ninety-nine".