99990238 has 4 divisors (see below), whose sum is σ = 149985360. Its totient is φ = 49995118.

The previous prime is 99990181. The next prime is 99990239. The reversal of 99990238 is 83209999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83209999 = 73 ⋅1139863.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 99990191 and 99990200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99990239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24997558 + ... + 24997561.

It is an arithmetic number, because the mean of its divisors is an integer number (37496340).

Almost surely, 2^99990238 is an apocalyptic number.

99990238 is a deficient number, since it is larger than the sum of its proper divisors (49995122).

99990238 is a wasteful number, since it uses less digits than its factorization.

99990238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49995121.

The product of its (nonzero) digits is 314928, while the sum is 49.

The square root of 99990238 is about 9999.5118880873. The cubic root of 99990238 is about 464.1437791397.

The spelling of 99990238 in words is "ninety-nine million, nine hundred ninety thousand, two hundred thirty-eight".