261673556 has 6 divisors (see below), whose sum is σ = 457928730. Its totient is φ = 130836776.

The previous prime is 261673499. The next prime is 261673589. The reversal of 261673556 is 655376162.

261673556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 235315600 + 26357956 = 15340^2 + 5134^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32709191 + ... + 32709198.

It is an arithmetic number, because the mean of its divisors is an integer number (76321455).

Almost surely, 2^261673556 is an apocalyptic number.

It is an amenable number.

261673556 is a deficient number, since it is larger than the sum of its proper divisors (196255174).

261673556 is a wasteful number, since it uses less digits than its factorization.

261673556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65418393 (or 65418391 counting only the distinct ones).

The product of its digits is 226800, while the sum is 41.

The square root of 261673556 is about 16176.3270243897. The cubic root of 261673556 is about 639.6169224441.

The spelling of 261673556 in words is "two hundred sixty-one million, six hundred seventy-three thousand, five hundred fifty-six".