261361552 has 20 divisors (see below), whose sum is σ = 518740236. Its totient is φ = 127493120.

The previous prime is 261361487. The next prime is 261361591. The reversal of 261361552 is 255163162.

It can be written as a sum of positive squares in 2 ways, for example, as 152868496 + 108493056 = 12364^2 + 10416^2 .

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 3 ways as a sum of consecutive naturals, for example, 198553 + ... + 199864.

Almost surely, 2^261361552 is an apocalyptic number.

It is an amenable number.

261361552 is a deficient number, since it is larger than the sum of its proper divisors (257378684).

261361552 is a wasteful number, since it uses less digits than its factorization.

261361552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398466 (or 398460 counting only the distinct ones).

The product of its digits is 10800, while the sum is 31.

The square root of 261361552 is about 16166.6803023997. The cubic root of 261361552 is about 639.3626076028.

The spelling of 261361552 in words is "two hundred sixty-one million, three hundred sixty-one thousand, five hundred fifty-two".