261530440 has 64 divisors (see below), whose sum is σ = 622972800. Its totient is φ = 98537472.

The previous prime is 261530411. The next prime is 261530441. The reversal of 261530440 is 44035162.

261530440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (261530441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 145789 + ... + 147571.

It is an arithmetic number, because the mean of its divisors is an integer number (9733950).

Almost surely, 2^261530440 is an apocalyptic number.

261530440 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 261530440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (311486400).

261530440 is an abundant number, since it is smaller than the sum of its proper divisors (361442360).

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

261530440 is a wasteful number, since it uses less digits than its factorization.

261530440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2006 (or 2002 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 261530440 is about 16171.9027946621. The cubic root of 261530440 is about 639.5002935288.

The spelling of 261530440 in words is "two hundred sixty-one million, five hundred thirty thousand, four hundred forty".