261640268 has 12 divisors (see below), whose sum is σ = 484804152. Its totient is φ = 123124800.

The previous prime is 261640259. The next prime is 261640289. The reversal of 261640268 is 862046162.

It is a super-2 number, since 2×261640268² = 136911259678223648, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1923758 + ... + 1923893.

It is an arithmetic number, because the mean of its divisors is an integer number (40400346).

Almost surely, 2^261640268 is an apocalyptic number.

It is an amenable number.

261640268 is a deficient number, since it is larger than the sum of its proper divisors (223163884).

261640268 is a wasteful number, since it uses less digits than its factorization.

261640268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3847672 (or 3847670 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 35.

The square root of 261640268 is about 16175.2980807155. The cubic root of 261640268 is about 639.5897989913.

The spelling of 261640268 in words is "two hundred sixty-one million, six hundred forty thousand, two hundred sixty-eight".