261899279 has 8 divisors (see below), whose sum is σ = 266174832. Its totient is φ = 257650560.

The previous prime is 261899257. The next prime is 261899293. The reversal of 261899279 is 972998162.

261899279 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261899279 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261899279.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261899219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13457 + ... + 26549.

It is an arithmetic number, because the mean of its divisors is an integer number (33271854).

Almost surely, 2^261899279 is an apocalyptic number.

261899279 is a deficient number, since it is larger than the sum of its proper divisors (4275553).

261899279 is a wasteful number, since it uses less digits than its factorization.

261899279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13417.

The product of its digits is 979776, while the sum is 53.

The square root of 261899279 is about 16183.3024750821. The cubic root of 261899279 is about 639.8007835355.

The spelling of 261899279 in words is "two hundred sixty-one million, eight hundred ninety-nine thousand, two hundred seventy-nine".