66528745 has 4 divisors (see below), whose sum is σ = 79834500. Its totient is φ = 53222992.

The previous prime is 66528739. The next prime is 66528767. The reversal of 66528745 is 54782566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30780304 + 35748441 = 5548^2 + 5979^2 .

It is a cyclic number.

It is not a de Polignac number, because 66528745 - 2⁵ = 66528713 is a prime.

It is a super-2 number, since 2×66528745² = 8852147822550050, which contains 22 as substring.

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, 6652870 + ... + 6652879.

It is an arithmetic number, because the mean of its divisors is an integer number (19958625).

Almost surely, 2^66528745 is an apocalyptic number.

It is an amenable number.

66528745 is a deficient number, since it is larger than the sum of its proper divisors (13305755).

66528745 is a wasteful number, since it uses less digits than its factorization.

66528745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13305754.

The product of its digits is 403200, while the sum is 43.

The square root of 66528745 is about 8156.5154937633. The cubic root of 66528745 is about 405.2003175076.

The spelling of 66528745 in words is "sixty-six million, five hundred twenty-eight thousand, seven hundred forty-five".