66667986 has 96 divisors (see below), whose sum is σ = 182227968. Its totient is φ = 17111520.

The previous prime is 66667973. The next prime is 66668027. The reversal of 66667986 is 68976666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 142525 + ... + 142991.

It is an arithmetic number, because the mean of its divisors is an integer number (1898208).

Almost surely, 2^66667986 is an apocalyptic number.

66667986 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 66667986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91113984).

66667986 is an abundant number, since it is smaller than the sum of its proper divisors (115559982).

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

66667986 is a wasteful number, since it uses less digits than its factorization.

66667986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596 (or 593 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 54.

The square root of 66667986 is about 8165.0466012142. The cubic root of 66667986 is about 405.4828078379.

The spelling of 66667986 in words is "sixty-six million, six hundred sixty-seven thousand, nine hundred eighty-six".