261504345 has 16 divisors (see below), whose sum is σ = 429716160. Its totient is φ = 135699264.

The previous prime is 261504329. The next prime is 261504359. The reversal of 261504345 is 543405162.

It is not a de Polignac number, because 261504345 - 2⁴ = 261504329 is a prime.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 235035 + ... + 236144.

It is an arithmetic number, because the mean of its divisors is an integer number (26857260).

Almost surely, 2^261504345 is an apocalyptic number.

It is an amenable number.

261504345 is a deficient number, since it is larger than the sum of its proper divisors (168211815).

261504345 is a wasteful number, since it uses less digits than its factorization.

261504345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471224.

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 261504345 is about 16171.0959739901. The cubic root of 261504345 is about 639.4790234551.

The spelling of 261504345 in words is "two hundred sixty-one million, five hundred four thousand, three hundred forty-five".