261121253 has 2 divisors, whose sum is σ = 261121254. Its totient is φ = 261121252.

The previous prime is 261121243. The next prime is 261121291. The reversal of 261121253 is 352121162.

261121253 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 243422404 + 17698849 = 15602^2 + 4207^2 .

It is a cyclic number.

It is not a de Polignac number, because 261121253 - 2⁸ = 261120997 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 (261121243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130560626 + 130560627.

It is an arithmetic number, because the mean of its divisors is an integer number (130560627).

Almost surely, 2^261121253 is an apocalyptic number.

It is an amenable number.

261121253 is a deficient number, since it is larger than the sum of its proper divisors (1).

261121253 is an equidigital number, since it uses as much as digits as its factorization.

261121253 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 23.

The square root of 261121253 is about 16159.2466717975. The cubic root of 261121253 is about 639.1666015928.

Subtracting 261121253 from its reverse (352121162), we obtain a palindrome (90999909).

The spelling of 261121253 in words is "two hundred sixty-one million, one hundred twenty-one thousand, two hundred fifty-three".