66528778 has 8 divisors (see below), whose sum is σ = 99920772. Its totient is φ = 33221856.

The previous prime is 66528767. The next prime is 66528793. The reversal of 66528778 is 87782566.

It can be written as a sum of positive squares in 2 ways, for example, as 59490369 + 7038409 = 7713^2 + 2653^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19275 + ... + 22462.

Almost surely, 2^66528778 is an apocalyptic number.

66528778 is a deficient number, since it is larger than the sum of its proper divisors (33391994).

66528778 is a wasteful number, since it uses less digits than its factorization.

66528778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42536.

The product of its digits is 1128960, while the sum is 49.

The square root of 66528778 is about 8156.5175166857. The cubic root of 66528778 is about 405.2003845042.

The spelling of 66528778 in words is "sixty-six million, five hundred twenty-eight thousand, seven hundred seventy-eight".