1664194247 has 2 divisors, whose sum is σ = 1664194248. Its totient is φ = 1664194246.

The previous prime is 1664194241. The next prime is 1664194289. The reversal of 1664194247 is 7424914661.

It is a weak prime.

It is an emirp because it is prime and its reverse (7424914661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1664194247 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1664194198 and 1664194207.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1664194241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832097123 + 832097124.

It is an arithmetic number, because the mean of its divisors is an integer number (832097124).

Almost surely, 2^1664194247 is an apocalyptic number.

1664194247 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664194247 is an equidigital number, since it uses as much as digits as its factorization.

1664194247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 44.

The square root of 1664194247 is about 40794.5369749431. The cubic root of 1664194247 is about 1185.0445358231.

The spelling of 1664194247 in words is "one billion, six hundred sixty-four million, one hundred ninety-four thousand, two hundred forty-seven".