261620577792 has 240 divisors, whose sum is σ = 864379676160. Its totient is φ = 74622283776.

The previous prime is 261620577749. The next prime is 261620577793. The reversal of 261620577792 is 297775026162.

It is a happy number.

261620577792 is a `hidden beast` number, since 2 + 6 + 1 + 62 + 0 + 577 + 7 + 9 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261620577793) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19959913 + ... + 19973015.

It is an arithmetic number, because the mean of its divisors is an integer number (3601581984).

Almost surely, 2^261620577792 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261620577792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (432189838080).

261620577792 is an abundant number, since it is smaller than the sum of its proper divisors (602759098368).

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

261620577792 is a wasteful number, since it uses less digits than its factorization.

261620577792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13753 (or 13734 counting only the distinct ones).

The product of its (nonzero) digits is 4445280, while the sum is 54.

The spelling of 261620577792 in words is "two hundred sixty-one billion, six hundred twenty million, five hundred seventy-seven thousand, seven hundred ninety-two".