261631441 has 4 divisors (see below), whose sum is σ = 261708084. Its totient is φ = 261554800.

The previous prime is 261631427. The next prime is 261631453. The reversal of 261631441 is 144136162.

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

It can be written as a sum of positive squares in 2 ways, for example, as 108243216 + 153388225 = 10404^2 + 12385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261631441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261631471) 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, 32950 + ... + 40111.

It is an arithmetic number, because the mean of its divisors is an integer number (65427021).

Almost surely, 2^261631441 is an apocalyptic number.

It is an amenable number.

261631441 is a deficient number, since it is larger than the sum of its proper divisors (76643).

261631441 is an equidigital number, since it uses as much as digits as its factorization.

261631441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76642.

The product of its digits is 3456, while the sum is 28.

The square root of 261631441 is about 16175.0252240916. The cubic root of 261631441 is about 639.5826062623.

The spelling of 261631441 in words is "two hundred sixty-one million, six hundred thirty-one thousand, four hundred forty-one".