66218380 has 24 divisors (see below), whose sum is σ = 145105632. Its totient is φ = 25335552.

The previous prime is 66218377. The next prime is 66218381. The reversal of 66218380 is 8381266.

It is not an unprimeable number, because it can be changed into a prime (66218381) 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, 71517 + ... + 72436.

It is an arithmetic number, because the mean of its divisors is an integer number (6046068).

Almost surely, 2^66218380 is an apocalyptic number.

It is an amenable number.

66218380 is an abundant number, since it is smaller than the sum of its proper divisors (78887252).

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

66218380 is a wasteful number, since it uses less digits than its factorization.

66218380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143985 (or 143983 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 66218380 is about 8137.4676650663. The cubic root of 66218380 is about 404.5692315659.

The spelling of 66218380 in words is "sixty-six million, two hundred eighteen thousand, three hundred eighty".