261243051 has 16 divisors (see below), whose sum is σ = 358308384. Its totient is φ = 169185024.

The previous prime is 261243023. The next prime is 261243077. The reversal of 261243051 is 150342162.

It is not a de Polignac number, because 261243051 - 2⁶ = 261242987 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261243011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86991 + ... + 89943.

It is an arithmetic number, because the mean of its divisors is an integer number (22394274).

Almost surely, 2^261243051 is an apocalyptic number.

261243051 is a deficient number, since it is larger than the sum of its proper divisors (97065333).

261243051 is a wasteful number, since it uses less digits than its factorization.

261243051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3790.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 261243051 is about 16163.0149105914. The cubic root of 261243051 is about 639.2659642605.

The spelling of 261243051 in words is "two hundred sixty-one million, two hundred forty-three thousand, fifty-one".