99900999 has 32 divisors (see below), whose sum is σ = 165838080. Its totient is φ = 58903200.

The previous prime is 99900971. The next prime is 99901001.

99900999 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 99900999 - 2⁵ = 99900967 is a prime.

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 (99900929) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6444 + ... + 15534.

It is an arithmetic number, because the mean of its divisors is an integer number (5182440).

Almost surely, 2^99900999 is an apocalyptic number.

99900999 is a gapful number since it is divisible by the number (99) formed by its first and last digit.

99900999 is a deficient number, since it is larger than the sum of its proper divisors (65937081).

99900999 is a wasteful number, since it uses less digits than its factorization.

99900999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9148 (or 9142 counting only the distinct ones).

The product of its (nonzero) digits is 531441, while the sum is 54.

The square root of 99900999 is about 9995.0487242434. The cubic root of 99900999 is about 464.0056588068.

It can be divided in two parts, 99900 and 999, that multiplied together give a square (99800100 = 9990²).

The spelling of 99900999 in words is "ninety-nine million, nine hundred thousand, nine hundred ninety-nine".