261322879 has 2 divisors, whose sum is σ = 261322880. Its totient is φ = 261322878.

The previous prime is 261322871. The next prime is 261322883. The reversal of 261322879 is 978223162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261322879 - 2³ = 261322871 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261322871) 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, 130661439 + 130661440.

It is an arithmetic number, because the mean of its divisors is an integer number (130661440).

Almost surely, 2^261322879 is an apocalyptic number.

261322879 is a deficient number, since it is larger than the sum of its proper divisors (1).

261322879 is an equidigital number, since it uses as much as digits as its factorization.

261322879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 40.

The square root of 261322879 is about 16165.4841869955. The cubic root of 261322879 is about 639.3310710977.

The spelling of 261322879 in words is "two hundred sixty-one million, three hundred twenty-two thousand, eight hundred seventy-nine".