261275040 has 288 divisors, whose sum is σ = 1017905616. Its totient is φ = 60456960.

The previous prime is 261275033. The next prime is 261275059. The reversal of 261275040 is 40572162.

261275040 is a `hidden beast` number, since 2 + 612 + 7 + 5 + 0 + 40 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 71166096 + 190108944 = 8436^2 + 13788^2 .

It is a tau number, because it is divible by the number of its divisors (288).

It is a junction number, because it is equal to n+sod(n) for n = 261274995 and 261275013.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 317830 + ... + 318650.

Almost surely, 2^261275040 is an apocalyptic number.

261275040 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 261275040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (508952808).

261275040 is an abundant number, since it is smaller than the sum of its proper divisors (756630576).

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

261275040 is a wasteful number, since it uses less digits than its factorization.

261275040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 872 (or 861 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 261275040 is about 16164.0044543424. The cubic root of 261275040 is about 639.2920557287.

The spelling of 261275040 in words is "two hundred sixty-one million, two hundred seventy-five thousand, forty".