66666512 has 80 divisors (see below), whose sum is σ = 150847488. Its totient is φ = 28237440.

The previous prime is 66666493. The next prime is 66666517. The reversal of 66666512 is 21566666.

It is a super-2 number, since 2×66666512² = 8888847644492288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66666517) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 173873 + ... + 174255.

Almost surely, 2^66666512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66666512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75423744).

66666512 is an abundant number, since it is smaller than the sum of its proper divisors (84180976).

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

66666512 is a wasteful number, since it uses less digits than its factorization.

66666512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 468 (or 462 counting only the distinct ones).

The product of its digits is 77760, while the sum is 38.

The square root of 66666512 is about 8164.9563379114. The cubic root of 66666512 is about 405.4798194667.

The spelling of 66666512 in words is "sixty-six million, six hundred sixty-six thousand, five hundred twelve".