1061691809 has 2 divisors, whose sum is σ = 1061691810. Its totient is φ = 1061691808.

The previous prime is 1061691797. The next prime is 1061691817. The reversal of 1061691809 is 9081961601.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1002355600 + 59336209 = 31660^2 + 7703^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1061691809 is a prime.

It is a super-2 number, since 2×1061691809² = 2254378994595384962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1061691859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 530845904 + 530845905.

It is an arithmetic number, because the mean of its divisors is an integer number (530845905).

Almost surely, 2^1061691809 is an apocalyptic number.

It is an amenable number.

1061691809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1061691809 is an equidigital number, since it uses as much as digits as its factorization.

1061691809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 1061691809 is about 32583.6125836286. The cubic root of 1061691809 is about 1020.1549838188.

The spelling of 1061691809 in words is "one billion, sixty-one million, six hundred ninety-one thousand, eight hundred nine".