89491391999 has 4 divisors (see below), whose sum is σ = 89493171336. Its totient is φ = 89489612664.

The previous prime is 89491391987. The next prime is 89491392013. The reversal of 89491391999 is 99919319498.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-89491391999 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 (89491391599) 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, 811964 + ... + 915569.

It is an arithmetic number, because the mean of its divisors is an integer number (22373292834).

Almost surely, 2^89491391999 is an apocalyptic number.

89491391999 is a deficient number, since it is larger than the sum of its proper divisors (1779337).

89491391999 is a wasteful number, since it uses less digits than its factorization.

89491391999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1779336.

The product of its digits is 51018336, while the sum is 71.

The spelling of 89491391999 in words is "eighty-nine billion, four hundred ninety-one million, three hundred ninety-one thousand, nine hundred ninety-nine".