66241666566 has 32 divisors (see below), whose sum is σ = 147256780800. Its totient is φ = 22072593960.

The previous prime is 66241666553. The next prime is 66241666573. The reversal of 66241666566 is 66566614266.

It is a super-2 number, since 2×66241666566² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69046 + ... + 370473.

It is an arithmetic number, because the mean of its divisors is an integer number (4601774400).

Almost surely, 2^66241666566 is an apocalyptic number.

66241666566 is an abundant number, since it is smaller than the sum of its proper divisors (81015114234).

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

66241666566 is a wasteful number, since it uses less digits than its factorization.

66241666566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442321 (or 442315 counting only the distinct ones).

The product of its digits is 11197440, while the sum is 54.

The spelling of 66241666566 in words is "sixty-six billion, two hundred forty-one million, six hundred sixty-six thousand, five hundred sixty-six".