91009008 has 50 divisors (see below), whose sum is σ = 263410224. Its totient is φ = 30335904.

The previous prime is 91009001. The next prime is 91009063. The reversal of 91009008 is 80090019.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91009001) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 33816 + ... + 36407.

Almost surely, 2^91009008 is an apocalyptic number.

It is an amenable number.

91009008 is an abundant number, since it is smaller than the sum of its proper divisors (172401216).

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

91009008 is a wasteful number, since it uses less digits than its factorization.

91009008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70243 (or 70228 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 91009008 is about 9539.8641499761. The cubic root of 91009008 is about 449.8089855970.

The spelling of 91009008 in words is "ninety-one million, nine thousand, eight".