1991736 has 32 divisors (see below), whose sum is σ = 5533200. Its totient is φ = 663840.

The previous prime is 1991729. The next prime is 1991753. The reversal of 1991736 is 6371991.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a plaindrome in base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 1991736.

It is a congruent number.

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, 4395 + ... + 4826.

2^1991736 is an apocalyptic number.

It is an amenable number.

1991736 is an abundant number, since it is smaller than the sum of its proper divisors (3541464).

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

1991736 is a wasteful number, since it uses less digits than its factorization.

1991736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9236 (or 9226 counting only the distinct ones).

The product of its digits is 10206, while the sum is 36.

The square root of 1991736 is about 1411.2887727180. The cubic root of 1991736 is about 125.8183323004.

The spelling of 1991736 in words is "one million, nine hundred ninety-one thousand, seven hundred thirty-six".