261831007 has 2 divisors, whose sum is σ = 261831008. Its totient is φ = 261831006.

The previous prime is 261830993. The next prime is 261831029. The reversal of 261831007 is 700138162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261831007 - 2¹⁵ = 261798239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261831067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130915503 + 130915504.

It is an arithmetic number, because the mean of its divisors is an integer number (130915504).

Almost surely, 2^261831007 is an apocalyptic number.

261831007 is a deficient number, since it is larger than the sum of its proper divisors (1).

261831007 is an equidigital number, since it uses as much as digits as its factorization.

261831007 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 261831007 is about 16181.1930029896. The cubic root of 261831007 is about 639.7451842032.

Adding to 261831007 its reverse (700138162), we get a palindrome (961969169).

The spelling of 261831007 in words is "two hundred sixty-one million, eight hundred thirty-one thousand, seven".