261347580 has 192 divisors, whose sum is σ = 891878400. Its totient is φ = 63141120.

The previous prime is 261347573. The next prime is 261347587. The reversal of 261347580 is 85743162.

261347580 is a `hidden beast` number, since 26 + 13 + 47 + 580 = 666.

It is an interprime number because it is at equal distance from previous prime (261347573) and next prime (261347587).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261347587) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 413865 + ... + 414495.

It is an arithmetic number, because the mean of its divisors is an integer number (4645200).

Almost surely, 2^261347580 is an apocalyptic number.

261347580 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 261347580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (445939200).

261347580 is an abundant number, since it is smaller than the sum of its proper divisors (630530820).

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

261347580 is a wasteful number, since it uses less digits than its factorization.

261347580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721 (or 713 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 261347580 is about 16166.2481732776. The cubic root of 261347580 is about 639.3512142750.

The spelling of 261347580 in words is "two hundred sixty-one million, three hundred forty-seven thousand, five hundred eighty".