668839397 has 2 divisors, whose sum is σ = 668839398. Its totient is φ = 668839396.

The previous prime is 668839393. The next prime is 668839403. The reversal of 668839397 is 793938866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 411846436 + 256992961 = 20294^2 + 16031^2 .

It is a cyclic number.

It is not a de Polignac number, because 668839397 - 2² = 668839393 is a prime.

It is a super-2 number, since 2×668839397² = 894692277958647218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668839393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334419698 + 334419699.

It is an arithmetic number, because the mean of its divisors is an integer number (334419699).

Almost surely, 2^668839397 is an apocalyptic number.

It is an amenable number.

668839397 is a deficient number, since it is larger than the sum of its proper divisors (1).

668839397 is an equidigital number, since it uses as much as digits as its factorization.

668839397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11757312, while the sum is 59.

The square root of 668839397 is about 25861.9294910492. The cubic root of 668839397 is about 874.5284629958.

The spelling of 668839397 in words is "six hundred sixty-eight million, eight hundred thirty-nine thousand, three hundred ninety-seven".