668451257 has 2 divisors, whose sum is σ = 668451258. Its totient is φ = 668451256.

The previous prime is 668451253. The next prime is 668451263. The reversal of 668451257 is 752154866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 385572496 + 282878761 = 19636^2 + 16819^2 .

It is a cyclic number.

It is not a de Polignac number, because 668451257 - 2² = 668451253 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (668451253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334225628 + 334225629.

It is an arithmetic number, because the mean of its divisors is an integer number (334225629).

Almost surely, 2^668451257 is an apocalyptic number.

It is an amenable number.

668451257 is a deficient number, since it is larger than the sum of its proper divisors (1).

668451257 is an equidigital number, since it uses as much as digits as its factorization.

668451257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 403200, while the sum is 44.

The square root of 668451257 is about 25854.4243215741. The cubic root of 668451257 is about 874.3592618586.

The spelling of 668451257 in words is "six hundred sixty-eight million, four hundred fifty-one thousand, two hundred fifty-seven".