99999890 has 16 divisors (see below), whose sum is σ = 180811008. Its totient is φ = 39819696.

The previous prime is 99999847. The next prime is 99999931. The reversal of 99999890 is 9899999.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20192 + ... + 24651.

It is an arithmetic number, because the mean of its divisors is an integer number (11300688).

Almost surely, 2^99999890 is an apocalyptic number.

99999890 is a deficient number, since it is larger than the sum of its proper divisors (80811118).

99999890 is a wasteful number, since it uses less digits than its factorization.

99999890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45073.

The product of its (nonzero) digits is 4251528, while the sum is 62.

The square root of 99999890 is about 9999.9944999985. The cubic root of 99999890 is about 464.1587131696.

The spelling of 99999890 in words is "ninety-nine million, nine hundred ninety-nine thousand, eight hundred ninety".