261686336 has 14 divisors (see below), whose sum is σ = 519283950. Its totient is φ = 130843136.

The previous prime is 261686323. The next prime is 261686357. The reversal of 261686336 is 633686162.

It can be written as a sum of positive squares in only one way, i.e., 241615936 + 20070400 = 15544^2 + 4480^2 .

It is a super-4 number, since 4×261686336⁴ (a number of 35 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 261686293 and 261686302.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2044361 + ... + 2044488.

Almost surely, 2^261686336 is an apocalyptic number.

It is an amenable number.

261686336 is a deficient number, since it is larger than the sum of its proper divisors (257597614).

261686336 is an equidigital number, since it uses as much as digits as its factorization.

261686336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4088861 (or 4088851 counting only the distinct ones).

The product of its digits is 186624, while the sum is 41.

The square root of 261686336 is about 16176.7220412542. The cubic root of 261686336 is about 639.6273351268.

The spelling of 261686336 in words is "two hundred sixty-one million, six hundred eighty-six thousand, three hundred thirty-six".