1691209423 has 2 divisors, whose sum is σ = 1691209424. Its totient is φ = 1691209422.

The previous prime is 1691209397. The next prime is 1691209529. The reversal of 1691209423 is 3249021961.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1691209423 - 2⁵ = 1691209391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1691909423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845604711 + 845604712.

It is an arithmetic number, because the mean of its divisors is an integer number (845604712).

Almost surely, 2^1691209423 is an apocalyptic number.

1691209423 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691209423 is an equidigital number, since it uses as much as digits as its factorization.

1691209423 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 37.

The square root of 1691209423 is about 41124.3166873323. The cubic root of 1691209423 is about 1191.4224975236.

The spelling of 1691209423 in words is "one billion, six hundred ninety-one million, two hundred nine thousand, four hundred twenty-three".