1209406091 has 2 divisors, whose sum is σ = 1209406092. Its totient is φ = 1209406090.

The previous prime is 1209406067. The next prime is 1209406147. The reversal of 1209406091 is 1906049021.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1209406091 is a prime.

It is not a weakly prime, because it can be changed into another prime (1209406291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 604703045 + 604703046.

It is an arithmetic number, because the mean of its divisors is an integer number (604703046).

Almost surely, 2^1209406091 is an apocalyptic number.

1209406091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1209406091 is an equidigital number, since it uses as much as digits as its factorization.

1209406091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 1209406091 is about 34776.5163724028. The cubic root of 1209406091 is about 1065.4278636724.

The spelling of 1209406091 in words is "one billion, two hundred nine million, four hundred six thousand, ninety-one".