261656541 has 16 divisors (see below), whose sum is σ = 387993600. Its totient is φ = 174278304.

The previous prime is 261656501. The next prime is 261656557. The reversal of 261656541 is 145656162.

261656541 is a `hidden beast` number, since 2 + 61 + 6 + 56 + 541 = 666.

It is not a de Polignac number, because 261656541 - 2¹⁷ = 261525469 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261656496 and 261656505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261656501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30745 + ... + 38321.

It is an arithmetic number, because the mean of its divisors is an integer number (24249600).

Almost surely, 2^261656541 is an apocalyptic number.

It is an amenable number.

261656541 is a deficient number, since it is larger than the sum of its proper divisors (126337059).

261656541 is a wasteful number, since it uses less digits than its factorization.

261656541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8865 (or 8859 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 261656541 is about 16175.8010929907. The cubic root of 261656541 is about 639.6030587099.

The spelling of 261656541 in words is "two hundred sixty-one million, six hundred fifty-six thousand, five hundred forty-one".