66128280 has 32 divisors (see below), whose sum is σ = 198385200. Its totient is φ = 17634176.

The previous prime is 66128267. The next prime is 66128311. The reversal of 66128280 is 8282166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 275415 + ... + 275654.

Almost surely, 2^66128280 is an apocalyptic number.

66128280 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66128280 is an abundant number, since it is smaller than the sum of its proper divisors (132256920).

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

66128280 is a wasteful number, since it uses less digits than its factorization.

66128280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 551083 (or 551079 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 66128280 is about 8131.9296602959. The cubic root of 66128280 is about 404.3856559840.

The spelling of 66128280 in words is "sixty-six million, one hundred twenty-eight thousand, two hundred eighty".