247628261 has 2 divisors, whose sum is σ = 247628262. Its totient is φ = 247628260.

The previous prime is 247628207. The next prime is 247628287. The reversal of 247628261 is 162826742.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 132388036 + 115240225 = 11506^2 + 10735^2 .

It is a cyclic number.

It is not a de Polignac number, because 247628261 - 2²⁶ = 180519397 is a prime.

It is a super-2 number, since 2×247628261² = 122639511291768242, which contains 22 as substring.

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 (247628201) 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, 123814130 + 123814131.

It is an arithmetic number, because the mean of its divisors is an integer number (123814131).

Almost surely, 2^247628261 is an apocalyptic number.

It is an amenable number.

247628261 is a deficient number, since it is larger than the sum of its proper divisors (1).

247628261 is an equidigital number, since it uses as much as digits as its factorization.

247628261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64512, while the sum is 38.

The square root of 247628261 is about 15736.2085967364. The cubic root of 247628261 is about 627.9620558369.

The spelling of 247628261 in words is "two hundred forty-seven million, six hundred twenty-eight thousand, two hundred sixty-one".