66506671 has 16 divisors (see below), whose sum is σ = 84614400. Its totient is φ = 51820440.

The previous prime is 66506641. The next prime is 66506683. The reversal of 66506671 is 17660566.

It is a happy number.

It is not a de Polignac number, because 66506671 - 2¹⁵ = 66473903 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66506671.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66506611) 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, 5041 + ... + 12586.

It is an arithmetic number, because the mean of its divisors is an integer number (5288400).

Almost surely, 2^66506671 is an apocalyptic number.

66506671 is a deficient number, since it is larger than the sum of its proper divisors (18107729).

66506671 is a wasteful number, since it uses less digits than its factorization.

66506671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17659 (or 17645 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 66506671 is about 8155.1622301460. The cubic root of 66506671 is about 405.1554978774.

The spelling of 66506671 in words is "sixty-six million, five hundred six thousand, six hundred seventy-one".