261284381 has 2 divisors, whose sum is σ = 261284382. Its totient is φ = 261284380.

The previous prime is 261284377. The next prime is 261284453. The reversal of 261284381 is 183482162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 245204281 + 16080100 = 15659^2 + 4010^2 .

It is a cyclic number.

It is not a de Polignac number, because 261284381 - 2² = 261284377 is a prime.

It is a super-2 number, since 2×261284381² = 136539055509106322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261284351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130642190 + 130642191.

It is an arithmetic number, because the mean of its divisors is an integer number (130642191).

Almost surely, 2^261284381 is an apocalyptic number.

It is an amenable number.

261284381 is a deficient number, since it is larger than the sum of its proper divisors (1).

261284381 is an equidigital number, since it uses as much as digits as its factorization.

261284381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18432, while the sum is 35.

The square root of 261284381 is about 16164.2933962484. The cubic root of 261284381 is about 639.2996742086.

The spelling of 261284381 in words is "two hundred sixty-one million, two hundred eighty-four thousand, three hundred eighty-one".