1067991 has 16 divisors (see below), whose sum is σ = 1545984. Its totient is φ = 653184.

The previous prime is 1067987. The next prime is 1067999. The reversal of 1067991 is 1997601.

1067991 is a nontrivial binomial coefficient, being equal to C(1462, 2).

It is not a de Polignac number, because 1067991 - 2² = 1067987 is a prime.

It is a super-2 number, since 2×1067991² = 2281209552162, which contains 22 as substring.

1067991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1067999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1950 + ... + 2436.

It is an arithmetic number, because the mean of its divisors is an integer number (96624).

2^1067991 is an apocalyptic number.

1067991 is the 1461-st triangular number and also the 731-st hexagonal number.

1067991 is a deficient number, since it is larger than the sum of its proper divisors (477993).

1067991 is a wasteful number, since it uses less digits than its factorization.

1067991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550.

The product of its (nonzero) digits is 3402, while the sum is 33.

The square root of 1067991 is about 1033.4365002263. The cubic root of 1067991 is about 102.2168588781.

The spelling of 1067991 in words is "one million, sixty-seven thousand, nine hundred ninety-one".