66405860 has 24 divisors (see below), whose sum is σ = 140461440. Its totient is φ = 26370144.

The previous prime is 66405841. The next prime is 66405869. The reversal of 66405860 is 6850466.

It is a self number, because there is not a number n which added to its sum of digits gives 66405860.

It is not an unprimeable number, because it can be changed into a prime (66405869) 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, 9164 + ... + 14723.

It is an arithmetic number, because the mean of its divisors is an integer number (5852560).

Almost surely, 2^66405860 is an apocalyptic number.

It is an amenable number.

66405860 is an abundant number, since it is smaller than the sum of its proper divisors (74055580).

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

66405860 is a wasteful number, since it uses less digits than its factorization.

66405860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24035 (or 24033 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 66405860 is about 8148.9790771605. The cubic root of 66405860 is about 404.9506824061.

The spelling of 66405860 in words is "sixty-six million, four hundred five thousand, eight hundred sixty".