261489880 has 32 divisors (see below), whose sum is σ = 602038800. Its totient is φ = 102162816.

The previous prime is 261489857. The next prime is 261489881. The reversal of 261489880 is 88984162.

It is a self number, because there is not a number n which added to its sum of digits gives 261489880.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261489881) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 74295 + ... + 77734.

Almost surely, 2^261489880 is an apocalyptic number.

261489880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261489880 is an abundant number, since it is smaller than the sum of its proper divisors (340548920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261489880 is a wasteful number, since it uses less digits than its factorization.

261489880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152083 (or 152079 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 46.

The square root of 261489880 is about 16170.6487192073. The cubic root of 261489880 is about 639.4672324023.

The spelling of 261489880 in words is "two hundred sixty-one million, four hundred eighty-nine thousand, eight hundred eighty".