16521006563 has 2 divisors, whose sum is σ = 16521006564. Its totient is φ = 16521006562.

The previous prime is 16521006547. The next prime is 16521006577. The reversal of 16521006563 is 36560012561.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16521006563 - 2⁴ = 16521006547 is a prime.

It is not a weakly prime, because it can be changed into another prime (16521006533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8260503281 + 8260503282.

It is an arithmetic number, because the mean of its divisors is an integer number (8260503282).

Almost surely, 2^16521006563 is an apocalyptic number.

16521006563 is a deficient number, since it is larger than the sum of its proper divisors (1).

16521006563 is an equidigital number, since it uses as much as digits as its factorization.

16521006563 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 35.

The spelling of 16521006563 in words is "sixteen billion, five hundred twenty-one million, six thousand, five hundred sixty-three".