666739237 has 2 divisors, whose sum is σ = 666739238. Its totient is φ = 666739236.

The previous prime is 666739231. The next prime is 666739243. The reversal of 666739237 is 732937666.

It is a balanced prime because it is at equal distance from previous prime (666739231) and next prime (666739243).

It can be written as a sum of positive squares in only one way, i.e., 461648196 + 205091041 = 21486^2 + 14321^2 .

It is a cyclic number.

It is not a de Polignac number, because 666739237 - 2⁷ = 666739109 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666739231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333369618 + 333369619.

It is an arithmetic number, because the mean of its divisors is an integer number (333369619).

Almost surely, 2^666739237 is an apocalyptic number.

It is an amenable number.

666739237 is a deficient number, since it is larger than the sum of its proper divisors (1).

666739237 is an equidigital number, since it uses as much as digits as its factorization.

666739237 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1714608, while the sum is 49.

The square root of 666739237 is about 25821.2942549362. The cubic root of 666739237 is about 873.6121615990.

The spelling of 666739237 in words is "six hundred sixty-six million, seven hundred thirty-nine thousand, two hundred thirty-seven".