1098721 has 8 divisors (see below), whose sum is σ = 1191680. Its totient is φ = 1006992.

The previous prime is 1098709. The next prime is 1098731. The reversal of 1098721 is 1278901.

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 1098721 - 2⁵ = 1098689 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

1098721 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1098721.

It is not an unprimeable number, because it can be changed into a prime (1098731) 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, 2710 + ... + 3088.

It is an arithmetic number, because the mean of its divisors is an integer number (148960).

2^1098721 is an apocalyptic number.

It is an amenable number.

1098721 is a deficient number, since it is larger than the sum of its proper divisors (92959).

1098721 is a wasteful number, since it uses less digits than its factorization.

1098721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 1098721 is about 1048.1989315011. The cubic root of 1098721 is about 103.1879873544.

The spelling of 1098721 in words is "one million, ninety-eight thousand, seven hundred twenty-one".