66485991 has 48 divisors (see below), whose sum is σ = 106923488. Its totient is φ = 36495360.

The previous prime is 66485989. The next prime is 66485999. The reversal of 66485991 is 19958466.

It is not a de Polignac number, because 66485991 - 2¹ = 66485989 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 66485991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66485999) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 344391 + ... + 344583.

Almost surely, 2^66485991 is an apocalyptic number.

66485991 is a deficient number, since it is larger than the sum of its proper divisors (40437497).

66485991 is a wasteful number, since it uses less digits than its factorization.

66485991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304 (or 293 counting only the distinct ones).

The product of its digits is 466560, while the sum is 48.

The square root of 66485991 is about 8153.8942230078. The cubic root of 66485991 is about 405.1134996631.

It can be divided in two parts, 66485 and 991, that added together give a palindrome (67476).

The spelling of 66485991 in words is "sixty-six million, four hundred eighty-five thousand, nine hundred ninety-one".