66813311 has 4 divisors (see below), whose sum is σ = 67945800. Its totient is φ = 65680824.

The previous prime is 66813301. The next prime is 66813317. The reversal of 66813311 is 11331866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66813311 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 (66813317) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 566156 + ... + 566273.

It is an arithmetic number, because the mean of its divisors is an integer number (16986450).

Almost surely, 2^66813311 is an apocalyptic number.

66813311 is a deficient number, since it is larger than the sum of its proper divisors (1132489).

66813311 is a wasteful number, since it uses less digits than its factorization.

66813311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132488.

The product of its digits is 2592, while the sum is 29.

The square root of 66813311 is about 8173.9409711595. The cubic root of 66813311 is about 405.7772221314. Note that the first 3 decimals are identical.

The spelling of 66813311 in words is "sixty-six million, eight hundred thirteen thousand, three hundred eleven".