1028991 has 8 divisors (see below), whose sum is σ = 1378944. Its totient is φ = 682520.

The previous prime is 1028981. The next prime is 1028999. The reversal of 1028991 is 1998201.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1028991 - 2⁹ = 1028479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1028999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75 + ... + 1436.

It is an arithmetic number, because the mean of its divisors is an integer number (172368).

2^1028991 is an apocalyptic number.

1028991 is a deficient number, since it is larger than the sum of its proper divisors (349953).

1028991 is a wasteful number, since it uses less digits than its factorization.

1028991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1741.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 1028991 is about 1014.3919360878. The cubic root of 1028991 is about 100.9571755840.

The spelling of 1028991 in words is "one million, twenty-eight thousand, nine hundred ninety-one".