261271879 has 4 divisors (see below), whose sum is σ = 285023880. Its totient is φ = 237519880.

The previous prime is 261271873. The next prime is 261271889. The reversal of 261271879 is 978172162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261271879 - 2¹¹ = 261269831 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 (261271873) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11875984 + ... + 11876005.

It is an arithmetic number, because the mean of its divisors is an integer number (71255970).

Almost surely, 2^261271879 is an apocalyptic number.

261271879 is a deficient number, since it is larger than the sum of its proper divisors (23752001).

261271879 is a wasteful number, since it uses less digits than its factorization.

261271879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23752000.

The product of its digits is 84672, while the sum is 43.

The square root of 261271879 is about 16163.9066750585. The cubic root of 261271879 is about 639.2894775894.

The spelling of 261271879 in words is "two hundred sixty-one million, two hundred seventy-one thousand, eight hundred seventy-nine".