261564244 has 24 divisors (see below), whose sum is σ = 485934120. Its totient is φ = 122766336.

The previous prime is 261564221. The next prime is 261564263. The reversal of 261564244 is 442465162.

It can be written as a sum of positive squares in 4 ways, for example, as 97416900 + 164147344 = 9870^2 + 12812^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22152 + ... + 31840.

It is an arithmetic number, because the mean of its divisors is an integer number (20247255).

Almost surely, 2^261564244 is an apocalyptic number.

It is an amenable number.

261564244 is a deficient number, since it is larger than the sum of its proper divisors (224369876).

261564244 is a wasteful number, since it uses less digits than its factorization.

261564244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10107 (or 10105 counting only the distinct ones).

The product of its digits is 46080, while the sum is 34.

The square root of 261564244 is about 16172.9479069216. The cubic root of 261564244 is about 639.5278451165.

The spelling of 261564244 in words is "two hundred sixty-one million, five hundred sixty-four thousand, two hundred forty-four".