78379999 has 4 divisors (see below), whose sum is σ = 78581880. Its totient is φ = 78178120.

The previous prime is 78379993. The next prime is 78380009. The reversal of 78379999 is 99997387.

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

It is a cyclic number.

It is not a de Polignac number, because 78379999 - 2³ = 78379991 is a prime.

It is a super-2 number, since 2×78379999² = 12286848486480002, which contains 22 as substring.

It is a Duffinian number.

78379999 is a modest number, since divided by 9999 gives 7837 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78379991) 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, 100357 + ... + 101134.

It is an arithmetic number, because the mean of its divisors is an integer number (19645470).

Almost surely, 2^78379999 is an apocalyptic number.

78379999 is a deficient number, since it is larger than the sum of its proper divisors (201881).

78379999 is a wasteful number, since it uses less digits than its factorization.

78379999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201880.

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

The square root of 78379999 is about 8853.2479350801. The cubic root of 78379999 is about 427.9585931788.

The spelling of 78379999 in words is "seventy-eight million, three hundred seventy-nine thousand, nine hundred ninety-nine".