261585580 has 12 divisors (see below), whose sum is σ = 549329760. Its totient is φ = 104634224.

The previous prime is 261585551. The next prime is 261585587. The reversal of 261585580 is 85585162.

It is not an unprimeable number, because it can be changed into a prime (261585587) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6539620 + ... + 6539659.

It is an arithmetic number, because the mean of its divisors is an integer number (45777480).

Almost surely, 2^261585580 is an apocalyptic number.

261585580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261585580 is an abundant number, since it is smaller than the sum of its proper divisors (287744180).

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

261585580 is a wasteful number, since it uses less digits than its factorization.

261585580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13079288 (or 13079286 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 40.

The square root of 261585580 is about 16173.6075134770. The cubic root of 261585580 is about 639.5452335726.

The spelling of 261585580 in words is "two hundred sixty-one million, five hundred eighty-five thousand, five hundred eighty".