128566563 has 24 divisors (see below), whose sum is σ = 183124272. Its totient is φ = 80216064.

The previous prime is 128566553. The next prime is 128566567. The reversal of 128566563 is 365665821.

It is a happy number.

It is not a de Polignac number, because 128566563 - 2⁸ = 128566307 is a prime.

It is a super-2 number, since 2×128566563² = 33058722243265938, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (128566567) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 222531 + ... + 223107.

It is an arithmetic number, because the mean of its divisors is an integer number (7630178).

Almost surely, 2^128566563 is an apocalyptic number.

128566563 is a deficient number, since it is larger than the sum of its proper divisors (54557709).

128566563 is a wasteful number, since it uses less digits than its factorization.

128566563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 871 (or 854 counting only the distinct ones).

The product of its digits is 259200, while the sum is 42.

The square root of 128566563 is about 11338.7196367138. The cubic root of 128566563 is about 504.7108929138.

The spelling of 128566563 in words is "one hundred twenty-eight million, five hundred sixty-six thousand, five hundred sixty-three".