668142061 has 2 divisors, whose sum is σ = 668142062. Its totient is φ = 668142060.

The previous prime is 668142043. The next prime is 668142073. The reversal of 668142061 is 160241866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 639786436 + 28355625 = 25294^2 + 5325^2 .

It is a cyclic number.

It is not a de Polignac number, because 668142061 - 2¹⁷ = 668010989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668142001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334071030 + 334071031.

It is an arithmetic number, because the mean of its divisors is an integer number (334071031).

Almost surely, 2^668142061 is an apocalyptic number.

It is an amenable number.

668142061 is a deficient number, since it is larger than the sum of its proper divisors (1).

668142061 is an equidigital number, since it uses as much as digits as its factorization.

668142061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 668142061 is about 25848.4440730965. Note that the first 3 decimals coincide. The cubic root of 668142061 is about 874.2244277537.

The spelling of 668142061 in words is "six hundred sixty-eight million, one hundred forty-two thousand, sixty-one".