261604556 has 6 divisors (see below), whose sum is σ = 457807980. Its totient is φ = 130802276.

The previous prime is 261604543. The next prime is 261604579. The reversal of 261604556 is 655406162.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32700566 + ... + 32700573.

It is an arithmetic number, because the mean of its divisors is an integer number (76301330).

Almost surely, 2^261604556 is an apocalyptic number.

It is an amenable number.

261604556 is a deficient number, since it is larger than the sum of its proper divisors (196203424).

261604556 is a wasteful number, since it uses less digits than its factorization.

261604556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65401143 (or 65401141 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 261604556 is about 16174.1941375761. The cubic root of 261604556 is about 639.5606978768.

The spelling of 261604556 in words is "two hundred sixty-one million, six hundred four thousand, five hundred fifty-six".