261523745 has 16 divisors (see below), whose sum is σ = 366294528. Its totient is φ = 175513920.

The previous prime is 261523727. The next prime is 261523751. The reversal of 261523745 is 547325162.

It is not a de Polignac number, because 261523745 - 2¹⁰ = 261522721 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Duffinian number.

It is an unprimeable number.

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, 77846 + ... + 81135.

It is an arithmetic number, because the mean of its divisors is an integer number (22893408).

Almost surely, 2^261523745 is an apocalyptic number.

It is an amenable number.

261523745 is a deficient number, since it is larger than the sum of its proper divisors (104770783).

261523745 is a wasteful number, since it uses less digits than its factorization.

261523745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159040.

The product of its digits is 50400, while the sum is 35.

The square root of 261523745 is about 16171.6957985240. The cubic root of 261523745 is about 639.4948365592.

The spelling of 261523745 in words is "two hundred sixty-one million, five hundred twenty-three thousand, seven hundred forty-five".