1991815982722 has 8 divisors (see below), whose sum is σ = 2987981726796. Its totient is φ = 995822073792.

The previous prime is 1991815982711. The next prime is 1991815982753. The reversal of 1991815982722 is 2272895181991.

It can be written as a sum of positive squares in 2 ways, for example, as 1982714631921 + 9101350801 = 1408089^2 + 95401^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42929803 + ... + 42976174.

Almost surely, 2^{1991815982722} is an apocalyptic number.

1991815982722 is a deficient number, since it is larger than the sum of its proper divisors (996165744074).

1991815982722 is a wasteful number, since it uses less digits than its factorization.

1991815982722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85917572.

The product of its digits is 13063680, while the sum is 64.

The spelling of 1991815982722 in words is "one trillion, nine hundred ninety-one billion, eight hundred fifteen million, nine hundred eighty-two thousand, seven hundred twenty-two".