261281079 has 8 divisors (see below), whose sum is σ = 387083120. Its totient is φ = 174187368.

The previous prime is 261281077. The next prime is 261281093. The reversal of 261281079 is 970182162.

It is not a de Polignac number, because 261281079 - 2¹ = 261281077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261281077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4838512 + ... + 4838565.

It is an arithmetic number, because the mean of its divisors is an integer number (48385390).

Almost surely, 2^261281079 is an apocalyptic number.

261281079 is a deficient number, since it is larger than the sum of its proper divisors (125802041).

261281079 is an equidigital number, since it uses as much as digits as its factorization.

261281079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9677086 (or 9677080 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 261281079 is about 16164.1912572204. The cubic root of 261281079 is about 639.2969811322.

The spelling of 261281079 in words is "two hundred sixty-one million, two hundred eighty-one thousand, seventy-nine".