66567728 has 20 divisors (see below), whose sum is σ = 130426920. Its totient is φ = 32909184.

The previous prime is 66567719. The next prime is 66567737. The reversal of 66567728 is 82776566.

It is an interprime number because it is at equal distance from previous prime (66567719) and next prime (66567737).

It is a super-2 number, since 2×66567728² = 8862524822163968, which contains 22 as substring.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21950 + ... + 24797.

It is an arithmetic number, because the mean of its divisors is an integer number (6521346).

Almost surely, 2^66567728 is an apocalyptic number.

It is an amenable number.

66567728 is a deficient number, since it is larger than the sum of its proper divisors (63859192).

66567728 is a wasteful number, since it uses less digits than its factorization.

66567728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46844 (or 46838 counting only the distinct ones).

The product of its digits is 846720, while the sum is 47.

The square root of 66567728 is about 8158.9048284681. The cubic root of 66567728 is about 405.2794454080.

The spelling of 66567728 in words is "sixty-six million, five hundred sixty-seven thousand, seven hundred twenty-eight".