261424381 has 2 divisors, whose sum is σ = 261424382. Its totient is φ = 261424380.

The previous prime is 261424349. The next prime is 261424393. The reversal of 261424381 is 183424162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 236083225 + 25341156 = 15365^2 + 5034^2 .

It is a cyclic number.

It is not a de Polignac number, because 261424381 - 2⁵ = 261424349 is a prime.

It is a super-2 number, since 2×261424381² = 136685413962466322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261424081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130712190 + 130712191.

It is an arithmetic number, because the mean of its divisors is an integer number (130712191).

Almost surely, 2^261424381 is an apocalyptic number.

It is an amenable number.

261424381 is a deficient number, since it is larger than the sum of its proper divisors (1).

261424381 is an equidigital number, since it uses as much as digits as its factorization.

261424381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9216, while the sum is 31.

The square root of 261424381 is about 16168.6233489435. The cubic root of 261424381 is about 639.4138358656.

The spelling of 261424381 in words is "two hundred sixty-one million, four hundred twenty-four thousand, three hundred eighty-one".