668260081 has 2 divisors, whose sum is σ = 668260082. Its totient is φ = 668260080.

The previous prime is 668260037. The next prime is 668260091. The reversal of 668260081 is 180062866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 412739856 + 255520225 = 20316^2 + 15985^2 .

It is a cyclic number.

It is not a de Polignac number, because 668260081 - 2¹⁷ = 668129009 is a prime.

It is a super-2 number, since 2×668260081² = 893143071716253122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 668260081.

It is not a weakly prime, because it can be changed into another prime (668260091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334130040 + 334130041.

It is an arithmetic number, because the mean of its divisors is an integer number (334130041).

Almost surely, 2^668260081 is an apocalyptic number.

It is an amenable number.

668260081 is a deficient number, since it is larger than the sum of its proper divisors (1).

668260081 is an equidigital number, since it uses as much as digits as its factorization.

668260081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 668260081 is about 25850.7268950024. The cubic root of 668260081 is about 874.2758987898.

The spelling of 668260081 in words is "six hundred sixty-eight million, two hundred sixty thousand, eighty-one".