261776828 has 12 divisors (see below), whose sum is σ = 458710560. Its totient is φ = 130716672.

The previous prime is 261776789. The next prime is 261776843. The reversal of 261776828 is 828677162.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39476 + ... + 45627.

It is an arithmetic number, because the mean of its divisors is an integer number (38225880).

Almost surely, 2^261776828 is an apocalyptic number.

It is an amenable number.

261776828 is a deficient number, since it is larger than the sum of its proper divisors (196933732).

261776828 is a wasteful number, since it uses less digits than its factorization.

261776828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85876 (or 85874 counting only the distinct ones).

The product of its digits is 451584, while the sum is 47.

The square root of 261776828 is about 16179.5187814718. The cubic root of 261776828 is about 639.7010550456.

The spelling of 261776828 in words is "two hundred sixty-one million, seven hundred seventy-six thousand, eight hundred twenty-eight".