66655650 has 48 divisors (see below), whose sum is σ = 166891104. Its totient is φ = 17604480.

The previous prime is 66655613. The next prime is 66655661. The reversal of 66655650 is 5655666.

It is a happy number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66655599 and 66655608.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13974 + ... + 18126.

It is an arithmetic number, because the mean of its divisors is an integer number (3476898).

Almost surely, 2^66655650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66655650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83445552).

66655650 is an abundant number, since it is smaller than the sum of its proper divisors (100235454).

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

66655650 is a wasteful number, since it uses less digits than its factorization.

66655650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4275 (or 4270 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 39.

The square root of 66655650 is about 8164.2911511043. The cubic root of 66655650 is about 405.4577966105.

The spelling of 66655650 in words is "sixty-six million, six hundred fifty-five thousand, six hundred fifty".