391115228 has 96 divisors (see below), whose sum is σ = 863654400. Its totient is φ = 151200000.

The previous prime is 391115213. The next prime is 391115233. The reversal of 391115228 is 822511193.

It is a happy number.

It is a super-2 number, since 2×391115228² = 305942243146983968, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 391115194 and 391115203.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1558103 + ... + 1558353.

It is an arithmetic number, because the mean of its divisors is an integer number (8996400).

Almost surely, 2^391115228 is an apocalyptic number.

391115228 is a gapful number since it is divisible by the number (38) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391115228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (431827200).

391115228 is an abundant number, since it is smaller than the sum of its proper divisors (472539172).

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

391115228 is a wasteful number, since it uses less digits than its factorization.

391115228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411 (or 409 counting only the distinct ones).

The product of its digits is 4320, while the sum is 32.

The square root of 391115228 is about 19776.6333838700. The cubic root of 391115228 is about 731.3101062630.

The spelling of 391115228 in words is "three hundred ninety-one million, one hundred fifteen thousand, two hundred twenty-eight".