261255051 has 10 divisors (see below), whose sum is σ = 390270012. Its totient is φ = 174169980.

The previous prime is 261255041. The next prime is 261255053. The reversal of 261255051 is 150552162.

261255051 is a `hidden beast` number, since 2 + 61 + 2 + 550 + 51 = 666.

It is not a de Polignac number, because 261255051 - 2⁵ = 261255019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (261255053) 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 9 ways as a sum of consecutive naturals, for example, 1612605 + ... + 1612766.

Almost surely, 2^261255051 is an apocalyptic number.

261255051 is a deficient number, since it is larger than the sum of its proper divisors (129014961).

261255051 is an equidigital number, since it uses as much as digits as its factorization.

261255051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3225383 (or 3225374 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The square root of 261255051 is about 16163.3861242006. The cubic root of 261255051 is about 639.2757521752.

The spelling of 261255051 in words is "two hundred sixty-one million, two hundred fifty-five thousand, fifty-one".