66217249660 has 24 divisors (see below), whose sum is σ = 139322128176. Its totient is φ = 26436251520.

The previous prime is 66217249643. The next prime is 66217249667. The reversal of 66217249660 is 6694271266.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66217249667) 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, 3154801 + ... + 3175720.

It is an arithmetic number, because the mean of its divisors is an integer number (5805088674).

Almost surely, 2^66217249660 is an apocalyptic number.

It is an amenable number.

66217249660 is an abundant number, since it is smaller than the sum of its proper divisors (73104878516).

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

66217249660 is a wasteful number, since it uses less digits than its factorization.

66217249660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6331053 (or 6331051 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 49.

The spelling of 66217249660 in words is "sixty-six billion, two hundred seventeen million, two hundred forty-nine thousand, six hundred sixty".