261572224 has 32 divisors (see below), whose sum is σ = 526286340. Its totient is φ = 129484800.

The previous prime is 261572219. The next prime is 261572231. The reversal of 261572224 is 422275162.

It can be written as a sum of positive squares in 2 ways, for example, as 238146624 + 23425600 = 15432^2 + 4840^2 .

It is a tau number, because it is divible by the number of its divisors (32).

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, 2812 + ... + 23044.

Almost surely, 2^261572224 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261572224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263143170).

261572224 is an abundant number, since it is smaller than the sum of its proper divisors (264714116).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261572224 is a wasteful number, since it uses less digits than its factorization.

261572224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20348 (or 20336 counting only the distinct ones).

The product of its digits is 13440, while the sum is 31.

The square root of 261572224 is about 16173.1946133100. The cubic root of 261572224 is about 639.5343487836.

The spelling of 261572224 in words is "two hundred sixty-one million, five hundred seventy-two thousand, two hundred twenty-four".