77998890 has 32 divisors (see below), whose sum is σ = 198210240. Its totient is φ = 19576064.

The previous prime is 77998889. The next prime is 77998919. The reversal of 77998890 is 9889977.

It is a happy number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 77998890.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75960 + ... + 76979.

It is an arithmetic number, because the mean of its divisors is an integer number (6194070).

Almost surely, 2^77998890 is an apocalyptic number.

77998890 is an abundant number, since it is smaller than the sum of its proper divisors (120211350).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77998890 is a wasteful number, since it uses less digits than its factorization.

77998890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152966.

The product of its (nonzero) digits is 2286144, while the sum is 57.

The square root of 77998890 is about 8831.6980247289. The cubic root of 77998890 is about 427.2638413862.

The spelling of 77998890 in words is "seventy-seven million, nine hundred ninety-eight thousand, eight hundred ninety".