261539228 has 12 divisors (see below), whose sum is σ = 461298432. Its totient is φ = 129739680.

The previous prime is 261539209. The next prime is 261539251. The reversal of 261539228 is 822935162.

It is a junction number, because it is equal to n+sod(n) for n = 261539191 and 261539200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256913 + ... + 257928.

It is an arithmetic number, because the mean of its divisors is an integer number (38441536).

Almost surely, 2^261539228 is an apocalyptic number.

It is an amenable number.

261539228 is a deficient number, since it is larger than the sum of its proper divisors (199759204).

261539228 is a wasteful number, since it uses less digits than its factorization.

261539228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514972 (or 514970 counting only the distinct ones).

The product of its digits is 51840, while the sum is 38.

The square root of 261539228 is about 16172.1744981929. The cubic root of 261539228 is about 639.5074563223.

The spelling of 261539228 in words is "two hundred sixty-one million, five hundred thirty-nine thousand, two hundred twenty-eight".