261821632 has 28 divisors (see below), whose sum is σ = 521756640. Its totient is φ = 130355456.

The previous prime is 261821587. The next prime is 261821663. The reversal of 261821632 is 236128162.

It is a junction number, because it is equal to n+sod(n) for n = 261821594 and 261821603.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6738 + ... + 23854.

Almost surely, 2^261821632 is an apocalyptic number.

It is an amenable number.

261821632 is a deficient number, since it is larger than the sum of its proper divisors (259935008).

261821632 is a wasteful number, since it uses less digits than its factorization.

261821632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17368 (or 17358 counting only the distinct ones).

The product of its digits is 6912, while the sum is 31.

The square root of 261821632 is about 16180.9033122382. The cubic root of 261821632 is about 639.7375486386.

Adding to 261821632 its reverse (236128162), we get a palindrome (497949794).

The spelling of 261821632 in words is "two hundred sixty-one million, eight hundred twenty-one thousand, six hundred thirty-two".