66666660 has 48 divisors (see below), whose sum is σ = 187488000.
Its totient is φ = 17699584.
The previous prime is 66666653. The next prime is 66666667. The reversal of 66666660 is 6666666.
It can be divided in two parts, 6 and 6666660, that added together give a palindrome (6666666).
It is an interprime number because it is at equal distance from previous prime (66666653) and next prime (66666667).
It is a nialpdrome in base 10.
It is not an unprimeable number, because it can be changed into a prime (66666667) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12016 + ... + 16664.
It is an arithmetic number, because the mean of its divisors is an integer number (3906000).
Almost surely, 266666660 is an apocalyptic number.
66666660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.
It is an amenable number.
66666660 is an abundant number, since it is smaller than the sum of its proper divisors (120821340).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
66666660 is a wasteful number, since it uses less digits than its factorization.
66666660 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 4900 (or 4898 counting only the distinct ones).
The product of its (nonzero) digits is 279936, while the sum is 42.
The square root of 66666660 is about 8164.9654010290.
The cubic root of 66666660 is about 405.4801195222.
The spelling of 66666660 in words is "sixty-six million, six hundred sixty-six thousand, six hundred sixty".