1991012 has 12 divisors (see below), whose sum is σ = 3495660. Its totient is φ = 992256.

The previous prime is 1990987. The next prime is 1991027. The reversal of 1991012 is 2101991.

It can be written as a sum of positive squares in 2 ways, for example, as 1308736 + 682276 = 1144^2 + 826^2 .

It is a congruent number.

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, 1028 + ... + 2244.

It is an arithmetic number, because the mean of its divisors is an integer number (291305).

2^1991012 is an apocalyptic number.

It is an amenable number.

1991012 is a deficient number, since it is larger than the sum of its proper divisors (1504648).

1991012 is a wasteful number, since it uses less digits than its factorization.

1991012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1630 (or 1628 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 1991012 is about 1411.0322462651. The cubic root of 1991012 is about 125.8030853814.

The spelling of 1991012 in words is "one million, nine hundred ninety-one thousand, twelve".