260161721 has 2 divisors, whose sum is σ = 260161722. Its totient is φ = 260161720.

The previous prime is 260161691. The next prime is 260161723. The reversal of 260161721 is 127161062.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164121721 + 96040000 = 12811^2 + 9800^2 .

It is a cyclic number.

It is not a de Polignac number, because 260161721 - 2¹⁰ = 260160697 is a prime.

Together with 260161723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (260161723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130080860 + 130080861.

It is an arithmetic number, because the mean of its divisors is an integer number (130080861).

Almost surely, 2^260161721 is an apocalyptic number.

It is an amenable number.

260161721 is a deficient number, since it is larger than the sum of its proper divisors (1).

260161721 is an equidigital number, since it uses as much as digits as its factorization.

260161721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 260161721 is about 16129.5294723684. The cubic root of 260161721 is about 638.3827338660.

It can be divided in two parts, 2601 and 61721, that multiplied together give a triangular number (160536321 = T₁₇₉₁₈).

The spelling of 260161721 in words is "two hundred sixty million, one hundred sixty-one thousand, seven hundred twenty-one".