99993990 has 16 divisors (see below), whose sum is σ = 239985648. Its totient is φ = 26665056.

The previous prime is 99993947. The next prime is 99993991. The reversal of 99993990 is 9939999.

It is a super-2 number, since 2×99993990² = 19997596072240200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 99993990.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99993991) 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, 1666537 + ... + 1666596.

It is an arithmetic number, because the mean of its divisors is an integer number (14999103).

Almost surely, 2^99993990 is an apocalyptic number.

99993990 is an abundant number, since it is smaller than the sum of its proper divisors (139991658).

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

99993990 is a wasteful number, since it uses less digits than its factorization.

99993990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3333143.

The product of its (nonzero) digits is 1594323, while the sum is 57.

The square root of 99993990 is about 9999.6994954849. The cubic root of 99993990 is about 464.1495845254.

It can be divided in two parts, 9 and 9993990, that added together give a palindrome (9993999).

The spelling of 99993990 in words is "ninety-nine million, nine hundred ninety-three thousand, nine hundred ninety".