66851943 has 4 divisors (see below), whose sum is σ = 89135928. Its totient is φ = 44567960.

The previous prime is 66851929. The next prime is 66851947. The reversal of 66851943 is 34915866.

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

It is a cyclic number.

It is not a de Polignac number, because 66851943 - 2⁴ = 66851927 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66851895 and 66851904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66851947) 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, 11141988 + ... + 11141993.

It is an arithmetic number, because the mean of its divisors is an integer number (22283982).

Almost surely, 2^66851943 is an apocalyptic number.

66851943 is a deficient number, since it is larger than the sum of its proper divisors (22283985).

66851943 is a wasteful number, since it uses less digits than its factorization.

66851943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22283984.

The product of its digits is 155520, while the sum is 42.

The square root of 66851943 is about 8176.3037492500. The cubic root of 66851943 is about 405.8554149598.

The spelling of 66851943 in words is "sixty-six million, eight hundred fifty-one thousand, nine hundred forty-three".