1663660247 has 2 divisors, whose sum is σ = 1663660248. Its totient is φ = 1663660246.

The previous prime is 1663660237. The next prime is 1663660253. The reversal of 1663660247 is 7420663661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1663660247 - 2⁴ = 1663660231 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1663660237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831830123 + 831830124.

It is an arithmetic number, because the mean of its divisors is an integer number (831830124).

Almost surely, 2^1663660247 is an apocalyptic number.

1663660247 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663660247 is an equidigital number, since it uses as much as digits as its factorization.

1663660247 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 41.

The square root of 1663660247 is about 40787.9914558194. The cubic root of 1663660247 is about 1184.9177714785.

The spelling of 1663660247 in words is "one billion, six hundred sixty-three million, six hundred sixty thousand, two hundred forty-seven".