99777799 has 8 divisors (see below), whose sum is σ = 109927440. Its totient is φ = 89808000.

The previous prime is 99777781. The next prime is 99777803.

99777799 is nontrivially palindromic in base 10.

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 99777799 - 2⁵ = 99777767 is a prime.

It is a Duffinian number.

It is a zygodrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 99777799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99777779) 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, 43794 + ... + 46015.

It is an arithmetic number, because the mean of its divisors is an integer number (13740930).

Almost surely, 2^99777799 is an apocalyptic number.

99777799 is a deficient number, since it is larger than the sum of its proper divisors (10149641).

99777799 is a wasteful number, since it uses less digits than its factorization.

99777799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89921.

The product of its digits is 15752961, while the sum is 64.

The square root of 99777799 is about 9988.8837714732. The cubic root of 99777799 is about 463.8148398525.

It can be divided in two parts, 99777 and 799, that added together give a triangular number (100576 = T₄₄₈).

The spelling of 99777799 in words is "ninety-nine million, seven hundred seventy-seven thousand, seven hundred ninety-nine".