261088381 has 4 divisors (see below), whose sum is σ = 261125532. Its totient is φ = 261051232.

The previous prime is 261088351. The next prime is 261088403. The reversal of 261088381 is 183880162.

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 251222500 + 9865881 = 15850^2 + 3141^2 .

It is a cyclic number.

It is not a de Polignac number, because 261088381 - 2¹³ = 261080189 is a prime.

It is a super-2 number, since 2×261088381² = 136334285386402322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261088381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261088351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4456 + ... + 23281.

It is an arithmetic number, because the mean of its divisors is an integer number (65281383).

Almost surely, 2^261088381 is an apocalyptic number.

It is an amenable number.

261088381 is a deficient number, since it is larger than the sum of its proper divisors (37151).

261088381 is an equidigital number, since it uses as much as digits as its factorization.

261088381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37150.

The product of its (nonzero) digits is 18432, while the sum is 37.

The square root of 261088381 is about 16158.2295131614. The cubic root of 261088381 is about 639.1397793586.

The spelling of 261088381 in words is "two hundred sixty-one million, eighty-eight thousand, three hundred eighty-one".