98989991 has 4 divisors (see below), whose sum is σ = 99025800. Its totient is φ = 98954184.

The previous prime is 98989973. The next prime is 98989993. The reversal of 98989991 is 19998989.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 98989991 - 2²⁶ = 31881127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (98989993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13376 + ... + 19413.

It is an arithmetic number, because the mean of its divisors is an integer number (24756450).

Almost surely, 2^98989991 is an apocalyptic number.

98989991 is a deficient number, since it is larger than the sum of its proper divisors (35809).

98989991 is a wasteful number, since it uses less digits than its factorization.

98989991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35808.

The product of its digits is 3779136, while the sum is 62.

The square root of 98989991 is about 9949.3713871782. The cubic root of 98989991 is about 462.5909103980.

The spelling of 98989991 in words is "ninety-eight million, nine hundred eighty-nine thousand, nine hundred ninety-one".