1663546817 has 2 divisors, whose sum is σ = 1663546818. Its totient is φ = 1663546816.

The previous prime is 1663546813. The next prime is 1663546837. The reversal of 1663546817 is 7186453661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1064325376 + 599221441 = 32624^2 + 24479^2 .

It is a cyclic number.

It is not a de Polignac number, because 1663546817 - 2² = 1663546813 is a prime.

It is not a weakly prime, because it can be changed into another prime (1663546813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831773408 + 831773409.

It is an arithmetic number, because the mean of its divisors is an integer number (831773409).

Almost surely, 2^1663546817 is an apocalyptic number.

It is an amenable number.

1663546817 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663546817 is an equidigital number, since it uses as much as digits as its factorization.

1663546817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 725760, while the sum is 47.

The square root of 1663546817 is about 40786.6009493314. The cubic root of 1663546817 is about 1184.8908412449.

The spelling of 1663546817 in words is "one billion, six hundred sixty-three million, five hundred forty-six thousand, eight hundred seventeen".