261305051 has 8 divisors (see below), whose sum is σ = 308932320. Its totient is φ = 216252288.

The previous prime is 261305039. The next prime is 261305069. The reversal of 261305051 is 150503162.

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

It is not a de Polignac number, because 261305051 - 2⁶ = 261304987 is a prime.

It is a super-2 number, since 2×261305051² = 136560659356225202, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261305071) 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, 643406 + ... + 643811.

It is an arithmetic number, because the mean of its divisors is an integer number (38616540).

Almost surely, 2^261305051 is an apocalyptic number.

261305051 is a deficient number, since it is larger than the sum of its proper divisors (47627269).

261305051 is a wasteful number, since it uses less digits than its factorization.

261305051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1287253.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 261305051 is about 16164.9327558144. The cubic root of 261305051 is about 639.3165319274.

The spelling of 261305051 in words is "two hundred sixty-one million, three hundred five thousand, fifty-one".