1043991 has 12 divisors (see below), whose sum is σ = 1624168. Its totient is φ = 642384.

The previous prime is 1043981. The next prime is 1044019. The reversal of 1043991 is 1993401.

It is not a de Polignac number, because 1043991 - 2⁹ = 1043479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1043921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4345 + ... + 4578.

2^1043991 is an apocalyptic number.

1043991 is a deficient number, since it is larger than the sum of its proper divisors (580177).

1043991 is a wasteful number, since it uses less digits than its factorization.

1043991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8942 (or 8939 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 1043991 is about 1021.7587777944. The cubic root of 1043991 is about 101.4453749283.

It can be divided in two parts, 10439 and 91, that multiplied together give a palindrome (949949).

The spelling of 1043991 in words is "one million, forty-three thousand, nine hundred ninety-one".