261644441 has 8 divisors (see below), whose sum is σ = 268020480. Its totient is φ = 255302208.

The previous prime is 261644437. The next prime is 261644473. The reversal of 261644441 is 144446162.

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

It is a cyclic number.

It is not a de Polignac number, because 261644441 - 2² = 261644437 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261644398 and 261644407.

It is not an unprimeable number, because it can be changed into a prime (261640441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7580 + ... + 24098.

It is an arithmetic number, because the mean of its divisors is an integer number (33502560).

Almost surely, 2^261644441 is an apocalyptic number.

It is an amenable number.

261644441 is a deficient number, since it is larger than the sum of its proper divisors (6376039).

261644441 is a wasteful number, since it uses less digits than its factorization.

261644441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16903.

The product of its digits is 18432, while the sum is 32.

The square root of 261644441 is about 16175.4270731873. The cubic root of 261644441 is about 639.5931993267.

The spelling of 261644441 in words is "two hundred sixty-one million, six hundred forty-four thousand, four hundred forty-one".