666451229 has 2 divisors, whose sum is σ = 666451230. Its totient is φ = 666451228.

The previous prime is 666451171. The next prime is 666451271. The reversal of 666451229 is 922154666.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 466992100 + 199459129 = 21610^2 + 14123^2 .

It is a cyclic number.

It is not a de Polignac number, because 666451229 - 2²⁴ = 649674013 is a prime.

It is a super-2 number, since 2×666451229² = 888314481271220882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666451129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333225614 + 333225615.

It is an arithmetic number, because the mean of its divisors is an integer number (333225615).

Almost surely, 2^666451229 is an apocalyptic number.

It is an amenable number.

666451229 is a deficient number, since it is larger than the sum of its proper divisors (1).

666451229 is an equidigital number, since it uses as much as digits as its factorization.

666451229 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 41.

The square root of 666451229 is about 25815.7167051391. The cubic root of 666451229 is about 873.4863535295.

The spelling of 666451229 in words is "six hundred sixty-six million, four hundred fifty-one thousand, two hundred twenty-nine".