261054391 has 4 divisors (see below), whose sum is σ = 281135512. Its totient is φ = 240973272.

The previous prime is 261054377. The next prime is 261054413. The reversal of 261054391 is 193450162.

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

It is a cyclic number.

It is not a de Polignac number, because 261054391 - 2⁹ = 261053879 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 (261054331) 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, 10040541 + ... + 10040566.

It is an arithmetic number, because the mean of its divisors is an integer number (70283878).

Almost surely, 2^261054391 is an apocalyptic number.

261054391 is a deficient number, since it is larger than the sum of its proper divisors (20081121).

261054391 is a wasteful number, since it uses less digits than its factorization.

261054391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20081120.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 261054391 is about 16157.1776929017. The cubic root of 261054391 is about 639.1120425135.

The spelling of 261054391 in words is "two hundred sixty-one million, fifty-four thousand, three hundred ninety-one".