261138351 has 4 divisors (see below), whose sum is σ = 348184472. Its totient is φ = 174092232.

The previous prime is 261138349. The next prime is 261138373. The reversal of 261138351 is 153831162.

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

It is not a de Polignac number, because 261138351 - 2¹ = 261138349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261138391) 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 3 ways as a sum of consecutive naturals, for example, 43523056 + ... + 43523061.

It is an arithmetic number, because the mean of its divisors is an integer number (87046118).

Almost surely, 2^261138351 is an apocalyptic number.

261138351 is a deficient number, since it is larger than the sum of its proper divisors (87046121).

261138351 is an equidigital number, since it uses as much as digits as its factorization.

261138351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87046120.

The product of its digits is 4320, while the sum is 30.

The square root of 261138351 is about 16159.7757100772. The cubic root of 261138351 is about 639.1805519855.

The spelling of 261138351 in words is "two hundred sixty-one million, one hundred thirty-eight thousand, three hundred fifty-one".