66212651671 has 8 divisors (see below), whose sum is σ = 70111744560. Its totient is φ = 62314028928.

The previous prime is 66212651639. The next prime is 66212651677. The reversal of 66212651671 is 17615621266.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66212651671 - 2⁵ = 66212651639 is a prime.

It is a super-5 number, since 5×66212651671⁵ (a number of 55 digits) contains 55555 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66212651677) 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, 196405 + ... + 413521.

It is an arithmetic number, because the mean of its divisors is an integer number (8763968070).

Almost surely, 2^66212651671 is an apocalyptic number.

66212651671 is a deficient number, since it is larger than the sum of its proper divisors (3899092889).

66212651671 is a wasteful number, since it uses less digits than its factorization.

66212651671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235073.

The product of its digits is 181440, while the sum is 43.

The spelling of 66212651671 in words is "sixty-six billion, two hundred twelve million, six hundred fifty-one thousand, six hundred seventy-one".