668155277 has 2 divisors, whose sum is σ = 668155278. Its totient is φ = 668155276.

The previous prime is 668155211. The next prime is 668155291. The reversal of 668155277 is 772551866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 532409476 + 135745801 = 23074^2 + 11651^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668155277 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668157277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334077638 + 334077639.

It is an arithmetic number, because the mean of its divisors is an integer number (334077639).

Almost surely, 2^668155277 is an apocalyptic number.

It is an amenable number.

668155277 is a deficient number, since it is larger than the sum of its proper divisors (1).

668155277 is an equidigital number, since it uses as much as digits as its factorization.

668155277 is an evil number, because the sum of its binary digits is even.

The product of its digits is 705600, while the sum is 47.

The square root of 668155277 is about 25848.6997158464. The cubic root of 668155277 is about 874.2301918342.

The spelling of 668155277 in words is "six hundred sixty-eight million, one hundred fifty-five thousand, two hundred seventy-seven".