1991793936 has 40 divisors (see below), whose sum is σ = 5613238944. Its totient is φ = 603573760.

The previous prime is 1991793931. The next prime is 1991793949. The reversal of 1991793936 is 6393971991.

It is not an unprimeable number, because it can be changed into a prime (1991793931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1885641 + ... + 1886696.

Almost surely, 2^1991793936 is an apocalyptic number.

1991793936 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1991793936 is an abundant number, since it is smaller than the sum of its proper divisors (3621445008).

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

1991793936 is a wasteful number, since it uses less digits than its factorization.

1991793936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3772359 (or 3772353 counting only the distinct ones).

The product of its digits is 2480058, while the sum is 57.

The square root of 1991793936 is about 44629.5186619798. The cubic root of 1991793936 is about 1258.1955223120.

The spelling of 1991793936 in words is "one billion, nine hundred ninety-one million, seven hundred ninety-three thousand, nine hundred thirty-six".