77998 has 8 divisors (see below), whose sum is σ = 119160. Its totient is φ = 38280.

The previous prime is 77983. The next prime is 77999. The reversal of 77998 is 89977.

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

It is a self number, because there is not a number n which added to its sum of digits gives 77998.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77999) 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, 213 + ... + 448.

It is an arithmetic number, because the mean of its divisors is an integer number (14895).

2⁷⁷⁹⁹⁸ is an apocalyptic number.

77998 is a deficient number, since it is larger than the sum of its proper divisors (41162).

77998 is a wasteful number, since it uses less digits than its factorization.

77998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 722.

The product of its digits is 31752, while the sum is 40.

The square root of 77998 is about 279.2812202781. The cubic root of 77998 is about 42.7262216294.

The spelling of 77998 in words is "seventy-seven thousand, nine hundred ninety-eight".