991879008 has 48 divisors (see below), whose sum is σ = 2756844720. Its totient is φ = 311177216.

The previous prime is 991879001. The next prime is 991879013. The reversal of 991879008 is 800978199.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×991879008² = 1967647933022128128, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991879001) 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, 302253 + ... + 305516.

It is an arithmetic number, because the mean of its divisors is an integer number (57434265).

Almost surely, 2^991879008 is an apocalyptic number.

It is an amenable number.

991879008 is an abundant number, since it is smaller than the sum of its proper divisors (1764965712).

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

991879008 is a wasteful number, since it uses less digits than its factorization.

991879008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 607799 (or 607791 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 51.

The square root of 991879008 is about 31494.1106875555. The cubic root of 991879008 is about 997.2856415913.

The spelling of 991879008 in words is "nine hundred ninety-one million, eight hundred seventy-nine thousand, eight".