1563640913 has 2 divisors, whose sum is σ = 1563640914. Its totient is φ = 1563640912.

The previous prime is 1563640843. The next prime is 1563640919. The reversal of 1563640913 is 3190463651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1500167824 + 63473089 = 38732^2 + 7967^2 .

It is a cyclic number.

It is not a de Polignac number, because 1563640913 - 2²⁰ = 1562592337 is a prime.

It is not a weakly prime, because it can be changed into another prime (1563640919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 781820456 + 781820457.

It is an arithmetic number, because the mean of its divisors is an integer number (781820457).

Almost surely, 2^1563640913 is an apocalyptic number.

It is an amenable number.

1563640913 is a deficient number, since it is larger than the sum of its proper divisors (1).

1563640913 is an equidigital number, since it uses as much as digits as its factorization.

1563640913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 1563640913 is about 39542.8996534144. The cubic root of 1563640913 is about 1160.6795743035.

The spelling of 1563640913 in words is "one billion, five hundred sixty-three million, six hundred forty thousand, nine hundred thirteen".