261555650 has 48 divisors (see below), whose sum is σ = 495801600. Its totient is φ = 102643200.

The previous prime is 261555629. The next prime is 261555661. The reversal of 261555650 is 56555162.

261555650 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×261555650² = 136822716093845000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 261555650.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 965015 + ... + 965285.

It is an arithmetic number, because the mean of its divisors is an integer number (10329200).

Almost surely, 2^261555650 is an apocalyptic number.

261555650 is a deficient number, since it is larger than the sum of its proper divisors (234245950).

261555650 is a wasteful number, since it uses less digits than its factorization.

261555650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579 (or 574 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 35.

The square root of 261555650 is about 16172.6822141536. The cubic root of 261555650 is about 639.5208408940.

The spelling of 261555650 in words is "two hundred sixty-one million, five hundred fifty-five thousand, six hundred fifty".