66403290 has 64 divisors (see below), whose sum is σ = 169626240. Its totient is φ = 16588800.

The previous prime is 66403279. The next prime is 66403297. The reversal of 66403290 is 9230466.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (66403297) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54690 + ... + 55890.

It is an arithmetic number, because the mean of its divisors is an integer number (2650410).

Almost surely, 2^66403290 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66403290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84813120).

66403290 is an abundant number, since it is smaller than the sum of its proper divisors (103222950).

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

66403290 is a wasteful number, since it uses less digits than its factorization.

66403290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1327.

The product of its (nonzero) digits is 7776, while the sum is 30.

The square root of 66403290 is about 8148.8213871700. The cubic root of 66403290 is about 404.9454582854.

The spelling of 66403290 in words is "sixty-six million, four hundred three thousand, two hundred ninety".