66698220 has 24 divisors (see below), whose sum is σ = 186755184. Its totient is φ = 17786176.

The previous prime is 66698209. The next prime is 66698243. The reversal of 66698220 is 2289666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 555759 + ... + 555878.

It is an arithmetic number, because the mean of its divisors is an integer number (7781466).

Almost surely, 2^66698220 is an apocalyptic number.

66698220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66698220 is an abundant number, since it is smaller than the sum of its proper divisors (120056964).

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

66698220 is a wasteful number, since it uses less digits than its factorization.

66698220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1111649 (or 1111647 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 66698220 is about 8166.8978198579. The cubic root of 66698220 is about 405.5440941973.

The spelling of 66698220 in words is "sixty-six million, six hundred ninety-eight thousand, two hundred twenty".