261795240 has 480 divisors, whose sum is σ = 1094967720. Its totient is φ = 55738368.

The previous prime is 261795229. The next prime is 261795253. The reversal of 261795240 is 42597162.

261795240 is a `hidden beast` number, since 2 + 61 + 79 + 524 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 232440516 + 29354724 = 15246^2 + 5418^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 261795195 and 261795204.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 2698872 + ... + 2698968.

Almost surely, 2^261795240 is an apocalyptic number.

261795240 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 261795240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (547483860).

261795240 is an abundant number, since it is smaller than the sum of its proper divisors (833172480).

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

261795240 is a wasteful number, since it uses less digits than its factorization.

261795240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 261795240 is about 16180.0877624319. The cubic root of 261795240 is about 639.7160524256.

The spelling of 261795240 in words is "two hundred sixty-one million, seven hundred ninety-five thousand, two hundred forty".