261441540 has 48 divisors (see below), whose sum is σ = 813375360. Its totient is φ = 69717600.

The previous prime is 261441511. The next prime is 261441541. The reversal of 261441540 is 45144162.

261441540 is a `hidden beast` number, since 2 + 614 + 4 + 1 + 5 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (261441541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 241536 + ... + 242615.

It is an arithmetic number, because the mean of its divisors is an integer number (16945320).

Almost surely, 2^261441540 is an apocalyptic number.

261441540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261441540 is an abundant number, since it is smaller than the sum of its proper divisors (551933820).

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

261441540 is a wasteful number, since it uses less digits than its factorization.

261441540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484169 (or 484161 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 261441540 is about 16169.1539667356. The cubic root of 261441540 is about 639.4278252035.

The spelling of 261441540 in words is "two hundred sixty-one million, four hundred forty-one thousand, five hundred forty".