89999999 has 2 divisors, whose sum is σ = 90000000. Its totient is φ = 89999998.

The previous prime is 89999983. The next prime is 90000049. The reversal of 89999999 is 99999998.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 89999999 - 2⁴ = 89999983 is a prime.

89999999 is a modest number, since divided by 9999 gives 8999 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (89999969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 44999999 + 45000000.

It is an arithmetic number, because the mean of its divisors is an integer number (45000000).

Almost surely, 2^89999999 is an apocalyptic number.

89999999 is a deficient number, since it is larger than the sum of its proper divisors (1).

89999999 is an equidigital number, since it uses as much as digits as its factorization.

89999999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38263752, while the sum is 71.

The square root of 89999999 is about 9486.8329278005. The cubic root of 89999999 is about 448.1404729959.

Subtracting 89999999 from its reverse (99999998), we obtain a palindrome (9999999).

The spelling of 89999999 in words is "eighty-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".