28567566 has 48 divisors (see below), whose sum is σ = 65729664. Its totient is φ = 9294264.

The previous prime is 28567559. The next prime is 28567571. The reversal of 28567566 is 66576582.

28567566 is a `hidden beast` number, since 2 + 85 + 6 + 7 + 566 = 666.

It is a super-2 number, since 2×28567566² = 1632211654328712, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20215 + ... + 21581.

It is an arithmetic number, because the mean of its divisors is an integer number (1369368).

Almost surely, 2^28567566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28567566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32864832).

28567566 is an abundant number, since it is smaller than the sum of its proper divisors (37162098).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28567566 is a wasteful number, since it uses less digits than its factorization.

28567566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1427 (or 1415 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The square root of 28567566 is about 5344.8635155633. The cubic root of 28567566 is about 305.6969317685.

The spelling of 28567566 in words is "twenty-eight million, five hundred sixty-seven thousand, five hundred sixty-six".