1090909 has 2 divisors, whose sum is σ = 1090910. Its totient is φ = 1090908.

The previous prime is 1090897. The next prime is 1090919. The reversal of 1090909 is 9090901.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 558009 + 532900 = 747^2 + 730^2 .

It is an emirp because it is prime and its reverse (9090901) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1090909 - 2⁵ = 1090877 is a prime.

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

1090909 is a modest number, since divided by 909 gives 109 as remainder.

1090909 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1090919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545454 + 545455.

It is an arithmetic number, because the mean of its divisors is an integer number (545455).

2^1090909 is an apocalyptic number.

It is an amenable number.

1090909 is a deficient number, since it is larger than the sum of its proper divisors (1).

1090909 is an equidigital number, since it uses as much as digits as its factorization.

1090909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 729, while the sum is 28.

The square root of 1090909 is about 1044.4658922148. The cubic root of 1090909 is about 102.9428469805.

The spelling of 1090909 in words is "one million, ninety thousand, nine hundred nine".