1090721 has 2 divisors, whose sum is σ = 1090722. Its totient is φ = 1090720.

The previous prime is 1090717. The next prime is 1090757. The reversal of 1090721 is 1270901.

1090721 is nontrivially palindromic in base 2.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 960400 + 130321 = 980^2 + 361^2 .

It is an emirp because it is prime and its reverse (1270901) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1090721 - 2² = 1090717 is a prime.

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

It is equal to p₈₅₀₂₅ and since 1090721 and 85025 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 1090693 and 1090702.

It is not a weakly prime, because it can be changed into another prime (1090711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545360 + 545361.

It is an arithmetic number, because the mean of its divisors is an integer number (545361).

2^1090721 is an apocalyptic number.

It is an amenable number.

1090721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1090721 is an equidigital number, since it uses as much as digits as its factorization.

1090721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 1090721 is about 1044.3758901851. The cubic root of 1090721 is about 102.9369331456.

The spelling of 1090721 in words is "one million, ninety thousand, seven hundred twenty-one".