66985650 has 144 divisors (see below), whose sum is σ = 194407200. Its totient is φ = 16954560.

The previous prime is 66985631. The next prime is 66985673. The reversal of 66985650 is 5658966.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66985596 and 66985605.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1135321 + ... + 1135379.

It is an arithmetic number, because the mean of its divisors is an integer number (1350050).

Almost surely, 2^66985650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66985650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97203600).

66985650 is an abundant number, since it is smaller than the sum of its proper divisors (127421550).

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

66985650 is a wasteful number, since it uses less digits than its factorization.

66985650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 98 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The square root of 66985650 is about 8184.4761591686. The cubic root of 66985650 is about 406.1258113497.

The spelling of 66985650 in words is "sixty-six million, nine hundred eighty-five thousand, six hundred fifty".