2191991912 has 32 divisors (see below), whose sum is σ = 4638232800. Its totient is φ = 962001600.

The previous prime is 2191991891. The next prime is 2191991987.

2191991912 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 426914 + ... + 432017.

It is an arithmetic number, because the mean of its divisors is an integer number (144944775).

Almost surely, 2^2191991912 is an apocalyptic number.

2191991912 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

2191991912 is an abundant number, since it is smaller than the sum of its proper divisors (2446240888).

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

2191991912 is a wasteful number, since it uses less digits than its factorization.

2191991912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 858977 (or 858973 counting only the distinct ones).

The product of its digits is 26244, while the sum is 44.

The square root of 2191991912 is about 46818.7132672396. The cubic root of 2191991912 is about 1299.0114599292.

The spelling of 2191991912 in words is "two billion, one hundred ninety-one million, nine hundred ninety-one thousand, nine hundred twelve".