261935145616 has 45 divisors (see below), whose sum is σ = 530619273219. Its totient is φ = 125250811488.

The previous prime is 261935145551. The next prime is 261935145673. The reversal of 261935145616 is 616541539162.

The square root of 261935145616 is 511796.

It is a perfect power (a square), and thus also a powerful number.

261935145616 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×261935145616² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261935145616.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 47082451 + ... + 47088013.

Almost surely, 2^261935145616 is an apocalyptic number.

261935145616 is the 511796-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261935145616

261935145616 is an abundant number, since it is smaller than the sum of its proper divisors (268684127603).

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

261935145616 is an frugal number, since it uses more digits than its factorization.

261935145616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11180 (or 5588 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 49.

Multiplying 261935145616 by its sum of digits (49), we get a square (12834822135184 = 3582572²).

The spelling of 261935145616 in words is "two hundred sixty-one billion, nine hundred thirty-five million, one hundred forty-five thousand, six hundred sixteen".