66543911 has 6 divisors (see below), whose sum is σ = 77408280. Its totient is φ = 57037596.

The previous prime is 66543907. The next prime is 66543923. The reversal of 66543911 is 11934566.

It is not a de Polignac number, because 66543911 - 2² = 66543907 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66543901) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 678971 + ... + 679068.

It is an arithmetic number, because the mean of its divisors is an integer number (12901380).

Almost surely, 2^66543911 is an apocalyptic number.

66543911 is a deficient number, since it is larger than the sum of its proper divisors (10864369).

66543911 is a wasteful number, since it uses less digits than its factorization.

66543911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1358053 (or 1358046 counting only the distinct ones).

The product of its digits is 19440, while the sum is 35.

The square root of 66543911 is about 8157.4451269990. The cubic root of 66543911 is about 405.2311052075.

The spelling of 66543911 in words is "sixty-six million, five hundred forty-three thousand, nine hundred eleven".