666228187 has 2 divisors, whose sum is σ = 666228188. Its totient is φ = 666228186.

The previous prime is 666228169. The next prime is 666228191. The reversal of 666228187 is 781822666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666228187 - 2¹¹ = 666226139 is a prime.

It is not a weakly prime, because it can be changed into another prime (666228137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333114093 + 333114094.

It is an arithmetic number, because the mean of its divisors is an integer number (333114094).

Almost surely, 2^666228187 is an apocalyptic number.

666228187 is a deficient number, since it is larger than the sum of its proper divisors (1).

666228187 is an equidigital number, since it uses as much as digits as its factorization.

666228187 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 46.

The square root of 666228187 is about 25811.3964558294. The cubic root of 666228187 is about 873.3888990958.

The spelling of 666228187 in words is "six hundred sixty-six million, two hundred twenty-eight thousand, one hundred eighty-seven".