991853859 has 16 divisors (see below), whose sum is σ = 1336051584. Its totient is φ = 654480000.

The previous prime is 991853843. The next prime is 991853861. The reversal of 991853859 is 958358199.

It is not a de Polignac number, because 991853859 - 2⁴ = 991853843 is a prime.

It is a super-2 number, since 2×991853859² = 1967548155226383762, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 991853799 and 991853808.

It is not an unprimeable number, because it can be changed into a prime (991853869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118699 + ... + 126779.

It is an arithmetic number, because the mean of its divisors is an integer number (83503224).

Almost surely, 2^991853859 is an apocalyptic number.

991853859 is a deficient number, since it is larger than the sum of its proper divisors (344197725).

991853859 is a wasteful number, since it uses less digits than its factorization.

991853859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8498.

The product of its digits is 3499200, while the sum is 57.

The square root of 991853859 is about 31493.7114199010. The cubic root of 991853859 is about 997.2772128252.

The spelling of 991853859 in words is "nine hundred ninety-one million, eight hundred fifty-three thousand, eight hundred fifty-nine".