261404331 has 8 divisors (see below), whose sum is σ = 350035920. Its totient is φ = 173521152.

The previous prime is 261404329. The next prime is 261404333. The reversal of 261404331 is 133404162.

It is an interprime number because it is at equal distance from previous prime (261404329) and next prime (261404333).

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

It is not a de Polignac number, because 261404331 - 2¹ = 261404329 is a prime.

It is a super-2 number, since 2×261404331² = 136664448531115122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261404333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 186286 + ... + 187683.

It is an arithmetic number, because the mean of its divisors is an integer number (43754490).

Almost surely, 2^261404331 is an apocalyptic number.

261404331 is a deficient number, since it is larger than the sum of its proper divisors (88631589).

261404331 is a wasteful number, since it uses less digits than its factorization.

261404331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374205.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 261404331 is about 16168.0033090051. The cubic root of 261404331 is about 639.3974887864.

Adding to 261404331 its reverse (133404162), we get a palindrome (394808493).

The spelling of 261404331 in words is "two hundred sixty-one million, four hundred four thousand, three hundred thirty-one".