99779999 has 8 divisors (see below), whose sum is σ = 109482192. Its totient is φ = 90183040.

The previous prime is 99779989. The next prime is 99780059. The reversal of 99779999 is 99997799.

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 99779999 - 2²⁴ = 83002783 is a prime.

It is a Duffinian number.

99779999 is a modest number, since divided by 9999 gives 9977 as remainder.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99779989) 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, 24314 + ... + 28119.

It is an arithmetic number, because the mean of its divisors is an integer number (13685274).

Almost surely, 2^99779999 is an apocalyptic number.

99779999 is a deficient number, since it is larger than the sum of its proper divisors (9702193).

99779999 is a wasteful number, since it uses less digits than its factorization.

99779999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52617.

The product of its digits is 26040609, while the sum is 68.

The square root of 99779999 is about 9988.9938932807. The cubic root of 99779999 is about 463.8182487108.

The spelling of 99779999 in words is "ninety-nine million, seven hundred seventy-nine thousand, nine hundred ninety-nine".