391099008 has 128 divisors (see below), whose sum is σ = 1109384640. Its totient is φ = 121651200.

The previous prime is 391099001. The next prime is 391099013. The reversal of 391099008 is 800990193.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (391099001) 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, 1181403 + ... + 1181733.

Almost surely, 2^391099008 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391099008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (554692320).

391099008 is an abundant number, since it is smaller than the sum of its proper divisors (718285632).

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

391099008 is a wasteful number, since it uses less digits than its factorization.

391099008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546 (or 534 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 39.

The square root of 391099008 is about 19776.2232997102. The cubic root of 391099008 is about 731.2999966985.

The spelling of 391099008 in words is "three hundred ninety-one million, ninety-nine thousand, eight".