66678113 has 2 divisors, whose sum is σ = 66678114. Its totient is φ = 66678112.

The previous prime is 66678109. The next prime is 66678119. The reversal of 66678113 is 31187666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66308449 + 369664 = 8143^2 + 608^2 .

It is a cyclic number.

It is not a de Polignac number, because 66678113 - 2² = 66678109 is a prime.

It is not a weakly prime, because it can be changed into another prime (66678119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33339056 + 33339057.

It is an arithmetic number, because the mean of its divisors is an integer number (33339057).

Almost surely, 2^66678113 is an apocalyptic number.

It is an amenable number.

66678113 is a deficient number, since it is larger than the sum of its proper divisors (1).

66678113 is an equidigital number, since it uses as much as digits as its factorization.

66678113 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 38.

The square root of 66678113 is about 8165.6667210951. Note that the first 3 decimals coincide. The cubic root of 66678113 is about 405.5033380140.

The spelling of 66678113 in words is "sixty-six million, six hundred seventy-eight thousand, one hundred thirteen".