261197580 has 96 divisors (see below), whose sum is σ = 838204416. Its totient is φ = 59533056.

The previous prime is 261197549. The next prime is 261197611. The reversal of 261197580 is 85791162.

261197580 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (261197549) and next prime (261197611).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 203902 + ... + 205178.

It is an arithmetic number, because the mean of its divisors is an integer number (8731296).

Almost surely, 2^261197580 is an apocalyptic number.

261197580 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 261197580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (419102208).

261197580 is an abundant number, since it is smaller than the sum of its proper divisors (577006836).

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

261197580 is a wasteful number, since it uses less digits than its factorization.

261197580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1783 (or 1781 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 39.

The square root of 261197580 is about 16161.6082120561. The cubic root of 261197580 is about 639.2288726846.

The spelling of 261197580 in words is "two hundred sixty-one million, one hundred ninety-seven thousand, five hundred eighty".