1090981 has 4 divisors (see below), whose sum is σ = 1101100. Its totient is φ = 1080864.

The previous prime is 1090979. The next prime is 1090997. The reversal of 1090981 is 1890901.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 982081 + 108900 = 991^2 + 330^2 .

It is a cyclic number.

It is not a de Polignac number, because 1090981 - 2¹ = 1090979 is a prime.

It is a super-2 number, since 2×1090981² = 2380479084722, which contains 22 as substring.

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

It is the 1045-th Hogben number.

It is a Duffinian number.

1090981 is a modest number, since divided by 981 gives 109 as remainder.

1090981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1090181) by changing a digit.

It is a nontrivial repunit in base 1044.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4896 + ... + 5113.

It is an arithmetic number, because the mean of its divisors is an integer number (275275).

2^1090981 is an apocalyptic number.

It is an amenable number.

1090981 is a deficient number, since it is larger than the sum of its proper divisors (10119).

1090981 is a wasteful number, since it uses less digits than its factorization.

1090981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10118.

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 1090981 is about 1044.5003590234. The cubic root of 1090981 is about 102.9451116735.

The spelling of 1090981 in words is "one million, ninety thousand, nine hundred eighty-one".