261380520 has 96 divisors (see below), whose sum is σ = 880981920. Its totient is φ = 69698880.

The previous prime is 261380513. The next prime is 261380569. The reversal of 261380520 is 25083162.

261380520 is a `hidden beast` number, since 2 + 6 + 138 + 0 + 520 = 666.

261380520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3726 + ... + 23165.

It is an arithmetic number, because the mean of its divisors is an integer number (9176895).

Almost surely, 2^261380520 is an apocalyptic number.

261380520 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 261380520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (440490960).

261380520 is an abundant number, since it is smaller than the sum of its proper divisors (619601400).

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

261380520 is a wasteful number, since it uses less digits than its factorization.

261380520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26917 (or 26901 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 261380520 is about 16167.2669304369. The cubic root of 261380520 is about 639.3780742192.

The spelling of 261380520 in words is "two hundred sixty-one million, three hundred eighty thousand, five hundred twenty".