261631427 has 2 divisors, whose sum is σ = 261631428. Its totient is φ = 261631426.

The previous prime is 261631399. The next prime is 261631453. The reversal of 261631427 is 724136162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261631427 - 2⁸ = 261631171 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 261631393 and 261631402.

It is not a weakly prime, because it can be changed into another prime (261631457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130815713 + 130815714.

It is an arithmetic number, because the mean of its divisors is an integer number (130815714).

Almost surely, 2^261631427 is an apocalyptic number.

261631427 is a deficient number, since it is larger than the sum of its proper divisors (1).

261631427 is an equidigital number, since it uses as much as digits as its factorization.

261631427 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 32.

The square root of 261631427 is about 16175.0247913257. The cubic root of 261631427 is about 639.5825948541.

Adding to 261631427 its reverse (724136162), we get a palindrome (985767589).

It can be divided in two parts, 2616 and 31427, that added together give a palindrome (34043).

The spelling of 261631427 in words is "two hundred sixty-one million, six hundred thirty-one thousand, four hundred twenty-seven".