1991876 has 6 divisors (see below), whose sum is σ = 3485790. Its totient is φ = 995936.

The previous prime is 1991863. The next prime is 1991879. The reversal of 1991876 is 6781991.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1537600 + 454276 = 1240^2 + 674^2 .

It is not an unprimeable number, because it can be changed into a prime (1991879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 248981 + ... + 248988.

It is an arithmetic number, because the mean of its divisors is an integer number (580965).

2^1991876 is an apocalyptic number.

It is an amenable number.

1991876 is a deficient number, since it is larger than the sum of its proper divisors (1493914).

1991876 is a wasteful number, since it uses less digits than its factorization.

1991876 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497973 (or 497971 counting only the distinct ones).

The product of its digits is 27216, while the sum is 41.

The square root of 1991876 is about 1411.3383719009. The cubic root of 1991876 is about 125.8212801733.

The spelling of 1991876 in words is "one million, nine hundred ninety-one thousand, eight hundred seventy-six".