261523447 has 2 divisors, whose sum is σ = 261523448. Its totient is φ = 261523446.

The previous prime is 261523433. The next prime is 261523477. The reversal of 261523447 is 744325162.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261523447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261523477) 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, 130761723 + 130761724.

It is an arithmetic number, because the mean of its divisors is an integer number (130761724).

Almost surely, 2^261523447 is an apocalyptic number.

261523447 is a deficient number, since it is larger than the sum of its proper divisors (1).

261523447 is an equidigital number, since it uses as much as digits as its factorization.

261523447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40320, while the sum is 34.

The square root of 261523447 is about 16171.6865848927. The cubic root of 261523447 is about 639.4945936628.

It can be divided in two parts, 2615 and 23447, that added together give a palindrome (26062).

The spelling of 261523447 in words is "two hundred sixty-one million, five hundred twenty-three thousand, four hundred forty-seven".