261147240 has 192 divisors, whose sum is σ = 895527360. Its totient is φ = 68428800.

The previous prime is 261147239. The next prime is 261147241. The reversal of 261147240 is 42741162.

261147240 is a `hidden beast` number, since 2 + 611 + 4 + 7 + 2 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (261147239) and next prime (261147241).

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 (261147241) 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 47 ways as a sum of consecutive naturals, for example, 651040 + ... + 651440.

It is an arithmetic number, because the mean of its divisors is an integer number (4664205).

Almost surely, 2^261147240 is an apocalyptic number.

261147240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261147240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (447763680).

261147240 is an abundant number, since it is smaller than the sum of its proper divisors (634380120).

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

261147240 is a wasteful number, since it uses less digits than its factorization.

261147240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 494 (or 478 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 261147240 is about 16160.0507424946. The cubic root of 261147240 is about 639.1878043499.

The spelling of 261147240 in words is "two hundred sixty-one million, one hundred forty-seven thousand, two hundred forty".