1991708 has 12 divisors (see below), whose sum is σ = 3637200. Its totient is φ = 952512.

The previous prime is 1991707. The next prime is 1991723. The reversal of 1991708 is 8071991.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991707) 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, 10733 + ... + 10916.

It is an arithmetic number, because the mean of its divisors is an integer number (303100).

2^1991708 is an apocalyptic number.

It is an amenable number.

1991708 is a deficient number, since it is larger than the sum of its proper divisors (1645492).

1991708 is a wasteful number, since it uses less digits than its factorization.

1991708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21676 (or 21674 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 35.

The square root of 1991708 is about 1411.2788526723. The cubic root of 1991708 is about 125.8177427092.

The spelling of 1991708 in words is "one million, nine hundred ninety-one thousand, seven hundred eight".