99891817 has 4 divisors (see below), whose sum is σ = 101298816. Its totient is φ = 98484820.

The previous prime is 99891811. The next prime is 99891821. The reversal of 99891817 is 71819899.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71819899 = 2887 ⋅24877.

It is a cyclic number.

It is not a de Polignac number, because 99891817 - 2¹⁹ = 99367529 is a prime.

It is a super-2 number, since 2×99891817² = 19956750207122978, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99891811) 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, 703393 + ... + 703534.

It is an arithmetic number, because the mean of its divisors is an integer number (25324704).

Almost surely, 2^99891817 is an apocalyptic number.

It is an amenable number.

99891817 is a deficient number, since it is larger than the sum of its proper divisors (1406999).

99891817 is a wasteful number, since it uses less digits than its factorization.

99891817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1406998.

The product of its digits is 326592, while the sum is 52.

The square root of 99891817 is about 9994.5893862629. The cubic root of 99891817 is about 463.9914426310.

The spelling of 99891817 in words is "ninety-nine million, eight hundred ninety-one thousand, eight hundred seventeen".