261443564 has 12 divisors (see below), whose sum is σ = 457918104. Its totient is φ = 130609824.

The previous prime is 261443557. The next prime is 261443617. The reversal of 261443564 is 465344162.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22622 + ... + 32165.

It is an arithmetic number, because the mean of its divisors is an integer number (38159842).

Almost surely, 2^261443564 is an apocalyptic number.

It is an amenable number.

261443564 is a deficient number, since it is larger than the sum of its proper divisors (196474540).

261443564 is a wasteful number, since it uses less digits than its factorization.

261443564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55984 (or 55982 counting only the distinct ones).

The product of its digits is 69120, while the sum is 35.

The square root of 261443564 is about 16169.2165549231. The cubic root of 261443564 is about 639.4294752838.

The spelling of 261443564 in words is "two hundred sixty-one million, four hundred forty-three thousand, five hundred sixty-four".