261520275040 has 96 divisors (see below), whose sum is σ = 623976714144. Its totient is φ = 103570513920.

The previous prime is 261520275031. The next prime is 261520275053. The reversal of 261520275040 is 40572025162.

It is a junction number, because it is equal to n+sod(n) for n = 261520274987 and 261520275005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40348600 + ... + 40355080.

It is an arithmetic number, because the mean of its divisors is an integer number (6499757439).

Almost surely, 2^261520275040 is an apocalyptic number.

261520275040 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 261520275040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (311988357072).

261520275040 is an abundant number, since it is smaller than the sum of its proper divisors (362456439104).

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

261520275040 is a wasteful number, since it uses less digits than its factorization.

261520275040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8960 (or 8952 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 34.

The spelling of 261520275040 in words is "two hundred sixty-one billion, five hundred twenty million, two hundred seventy-five thousand, forty".