66013866 has 56 divisors (see below), whose sum is σ = 156342720. Its totient is φ = 20837736.

The previous prime is 66013837. The next prime is 66013949. The reversal of 66013866 is 66831066.

It is a self number, because there is not a number n which added to its sum of digits gives 66013866.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 26511 + ... + 28893.

Almost surely, 2^66013866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66013866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78171360).

66013866 is an abundant number, since it is smaller than the sum of its proper divisors (90328854).

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

66013866 is a wasteful number, since it uses less digits than its factorization.

66013866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2422 (or 2407 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 66013866 is about 8124.8917531251. The cubic root of 66013866 is about 404.1523010069.

The spelling of 66013866 in words is "sixty-six million, thirteen thousand, eight hundred sixty-six".