1991808022 has 8 divisors (see below), whose sum is σ = 3038351400. Its totient is φ = 979024224.

The previous prime is 1991807989. The next prime is 1991808023. The reversal of 1991808022 is 2208081991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991808023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8439747 + ... + 8439982.

It is an arithmetic number, because the mean of its divisors is an integer number (379793925).

Almost surely, 2^1991808022 is an apocalyptic number.

1991808022 is a deficient number, since it is larger than the sum of its proper divisors (1046543378).

1991808022 is a wasteful number, since it uses less digits than its factorization.

1991808022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16879790.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 1991808022 is about 44629.6764720516. The cubic root of 1991808022 is about 1258.1984882982.

The spelling of 1991808022 in words is "one billion, nine hundred ninety-one million, eight hundred eight thousand, twenty-two".