666819233 has 2 divisors, whose sum is σ = 666819234. Its totient is φ = 666819232.

The previous prime is 666819191. The next prime is 666819277. The reversal of 666819233 is 332918666.

It is an a-pointer prime, because the next prime (666819277) can be obtained adding 666819233 to its sum of digits (44).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 600103009 + 66716224 = 24497^2 + 8168^2 .

It is a cyclic number.

It is not a de Polignac number, because 666819233 - 2¹⁶ = 666753697 is a prime.

It is not a weakly prime, because it can be changed into another prime (666819133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333409616 + 333409617.

It is an arithmetic number, because the mean of its divisors is an integer number (333409617).

Almost surely, 2^666819233 is an apocalyptic number.

It is an amenable number.

666819233 is a deficient number, since it is larger than the sum of its proper divisors (1).

666819233 is an equidigital number, since it uses as much as digits as its factorization.

666819233 is an evil number, because the sum of its binary digits is even.

The product of its digits is 279936, while the sum is 44.

The square root of 666819233 is about 25822.8432400462. The cubic root of 666819233 is about 873.6470991377.

The spelling of 666819233 in words is "six hundred sixty-six million, eight hundred nineteen thousand, two hundred thirty-three".