91243009 has 8 divisors (see below), whose sum is σ = 107194752. Its totient is φ = 76567440.

The previous prime is 91243003. The next prime is 91243049. The reversal of 91243009 is 90034219.

It is a happy number.

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 91243009 - 2¹³ = 91234817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91243003) 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, 318889 + ... + 319174.

It is an arithmetic number, because the mean of its divisors is an integer number (13399344).

Almost surely, 2^91243009 is an apocalyptic number.

It is an amenable number.

91243009 is a deficient number, since it is larger than the sum of its proper divisors (15951743).

91243009 is a wasteful number, since it uses less digits than its factorization.

91243009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 638087.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 91243009 is about 9552.1206545981. The cubic root of 91243009 is about 450.1941697040.

The spelling of 91243009 in words is "ninety-one million, two hundred forty-three thousand, nine".