91838989 has 8 divisors (see below), whose sum is σ = 105461280. Its totient is φ = 79095600.

The previous prime is 91838963. The next prime is 91839017. The reversal of 91838989 is 98983819.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91838989 - 2⁷ = 91838861 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 (91838939) 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, 219502 + ... + 219919.

It is an arithmetic number, because the mean of its divisors is an integer number (13182660).

Almost surely, 2^91838989 is an apocalyptic number.

It is an amenable number.

91838989 is a deficient number, since it is larger than the sum of its proper divisors (13622291).

91838989 is a wasteful number, since it uses less digits than its factorization.

91838989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439451.

The product of its digits is 1119744, while the sum is 55.

The square root of 91838989 is about 9583.2660925177. The cubic root of 91838989 is about 451.1722342542.

The spelling of 91838989 in words is "ninety-one million, eight hundred thirty-eight thousand, nine hundred eighty-nine".