261824761 has 9 divisors (see below), whose sum is σ = 287986629. Its totient is φ = 237860700.

The previous prime is 261824747. The next prime is 261824779. The reversal of 261824761 is 167428162.

The square root of 261824761 is 16181.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 261824761 - 2¹¹ = 261822713 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261824761.

It is not an unprimeable number, because it can be changed into a prime (261824711) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 177256 + ... + 178726.

Almost surely, 2^261824761 is an apocalyptic number.

261824761 is the 16181-st square number.

261824761 is the 8091-st centered octagonal number.

It is an amenable number.

261824761 is a deficient number, since it is larger than the sum of its proper divisors (26161868).

261824761 is an frugal number, since it uses more digits than its factorization.

261824761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2964 (or 1482 counting only the distinct ones).

The product of its digits is 32256, while the sum is 37.

The cubic root of 261824761 is about 639.7400971049.

The spelling of 261824761 in words is "two hundred sixty-one million, eight hundred twenty-four thousand, seven hundred sixty-one".