66217290 has 16 divisors (see below), whose sum is σ = 158921568. Its totient is φ = 17657936.

The previous prime is 66217289. The next prime is 66217297. The reversal of 66217290 is 9271266.

It is not an unprimeable number, because it can be changed into a prime (66217297) 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, 1103592 + ... + 1103651.

It is an arithmetic number, because the mean of its divisors is an integer number (9932598).

Almost surely, 2^66217290 is an apocalyptic number.

66217290 is an abundant number, since it is smaller than the sum of its proper divisors (92704278).

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

66217290 is a wasteful number, since it uses less digits than its factorization.

66217290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2207253.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 66217290 is about 8137.4006906383. The cubic root of 66217290 is about 404.5670117246.

The spelling of 66217290 in words is "sixty-six million, two hundred seventeen thousand, two hundred ninety".