268515721 has 2 divisors, whose sum is σ = 268515722. Its totient is φ = 268515720.

The previous prime is 268515673. The next prime is 268515739. The reversal of 268515721 is 127515862.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171217225 + 97298496 = 13085^2 + 9864^2 .

It is a cyclic number.

It is not a de Polignac number, because 268515721 - 2¹¹ = 268513673 is a prime.

It is not a weakly prime, because it can be changed into another prime (268515761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 134257860 + 134257861.

It is an arithmetic number, because the mean of its divisors is an integer number (134257861).

Almost surely, 2^268515721 is an apocalyptic number.

It is an amenable number.

268515721 is a deficient number, since it is larger than the sum of its proper divisors (1).

268515721 is an equidigital number, since it uses as much as digits as its factorization.

268515721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 33600, while the sum is 37.

The square root of 268515721 is about 16386.4493103296. The cubic root of 268515721 is about 645.1438663120.

The spelling of 268515721 in words is "two hundred sixty-eight million, five hundred fifteen thousand, seven hundred twenty-one".