260780021 has 2 divisors, whose sum is σ = 260780022. Its totient is φ = 260780020.

The previous prime is 260780011. The next prime is 260780071. The reversal of 260780021 is 120087062.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 197402500 + 63377521 = 14050^2 + 7961^2 .

It is a cyclic number.

It is not a de Polignac number, because 260780021 - 2¹⁴ = 260763637 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (260780011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130390010 + 130390011.

It is an arithmetic number, because the mean of its divisors is an integer number (130390011).

Almost surely, 2^260780021 is an apocalyptic number.

It is an amenable number.

260780021 is a deficient number, since it is larger than the sum of its proper divisors (1).

260780021 is an equidigital number, since it uses as much as digits as its factorization.

260780021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 260780021 is about 16148.6848071290. The cubic root of 260780021 is about 638.8880602765. Note that the first 3 decimals are identical.

It can be divided in two parts, 2607 and 80021, that added together give a palindrome (82628).

The spelling of 260780021 in words is "two hundred sixty million, seven hundred eighty thousand, twenty-one".