261344545 has 32 divisors (see below), whose sum is σ = 392014080. Its totient is φ = 162493440.

The previous prime is 261344543. The next prime is 261344597. The reversal of 261344545 is 545443162.

It is not a de Polignac number, because 261344545 - 2¹ = 261344543 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261344545.

It is not an unprimeable number, because it can be changed into a prime (261344543) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 218469 + ... + 219661.

It is an arithmetic number, because the mean of its divisors is an integer number (12250440).

Almost surely, 2^261344545 is an apocalyptic number.

It is an amenable number.

261344545 is a deficient number, since it is larger than the sum of its proper divisors (130669535).

261344545 is a wasteful number, since it uses less digits than its factorization.

261344545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1785.

The product of its digits is 57600, while the sum is 34.

The square root of 261344545 is about 16166.1543045958. The cubic root of 261344545 is about 639.3487393609.

The spelling of 261344545 in words is "two hundred sixty-one million, three hundred forty-four thousand, five hundred forty-five".