66428564 has 6 divisors (see below), whose sum is σ = 116249994. Its totient is φ = 33214280.

The previous prime is 66428543. The next prime is 66428611. The reversal of 66428564 is 46582466.

It can be written as a sum of positive squares in only one way, i.e., 65739664 + 688900 = 8108^2 + 830^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8303567 + ... + 8303574.

It is an arithmetic number, because the mean of its divisors is an integer number (19374999).

Almost surely, 2^66428564 is an apocalyptic number.

It is an amenable number.

66428564 is a deficient number, since it is larger than the sum of its proper divisors (49821430).

66428564 is a wasteful number, since it uses less digits than its factorization.

66428564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16607145 (or 16607143 counting only the distinct ones).

The product of its digits is 276480, while the sum is 41.

The square root of 66428564 is about 8150.3720160493. The cubic root of 66428564 is about 404.9968276945.

The spelling of 66428564 in words is "sixty-six million, four hundred twenty-eight thousand, five hundred sixty-four".