66851849 has 2 divisors, whose sum is σ = 66851850. Its totient is φ = 66851848.

The previous prime is 66851833. The next prime is 66851879. The reversal of 66851849 is 94815866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33582025 + 33269824 = 5795^2 + 5768^2 .

It is a cyclic number.

It is not a de Polignac number, because 66851849 - 2⁴ = 66851833 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66851809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33425924 + 33425925.

It is an arithmetic number, because the mean of its divisors is an integer number (33425925).

Almost surely, 2^66851849 is an apocalyptic number.

It is an amenable number.

66851849 is a deficient number, since it is larger than the sum of its proper divisors (1).

66851849 is an equidigital number, since it uses as much as digits as its factorization.

66851849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 414720, while the sum is 47.

The square root of 66851849 is about 8176.2980009293. The cubic root of 66851849 is about 405.8552247363.

The spelling of 66851849 in words is "sixty-six million, eight hundred fifty-one thousand, eight hundred forty-nine".