66670728 has 32 divisors (see below), whose sum is σ = 167789760. Its totient is φ = 22075200.

The previous prime is 66670727. The next prime is 66670729. The reversal of 66670728 is 82707666.

It is an interprime number because it is at equal distance from previous prime (66670727) and next prime (66670729).

It is a self number, because there is not a number n which added to its sum of digits gives 66670728.

It is not an unprimeable number, because it can be changed into a prime (66670727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5575 + ... + 12822.

It is an arithmetic number, because the mean of its divisors is an integer number (5243430).

Almost surely, 2^66670728 is an apocalyptic number.

It is an amenable number.

66670728 is an abundant number, since it is smaller than the sum of its proper divisors (101119032).

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

66670728 is a wasteful number, since it uses less digits than its factorization.

66670728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18557 (or 18553 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 42.

The square root of 66670728 is about 8165.2145103482. The cubic root of 66670728 is about 405.4883668209.

The spelling of 66670728 in words is "sixty-six million, six hundred seventy thousand, seven hundred twenty-eight".