261557120760 has 64 divisors (see below), whose sum is σ = 845030702880. Its totient is φ = 64383290880.

The previous prime is 261557120723. The next prime is 261557120771. The reversal of 261557120760 is 67021755162.

It is a happy number.

It is a super-2 number, since 2×261557120760² (a number of 24 digits) contains 22 as substring.

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, 83830851 + ... + 83833970.

Almost surely, 2^261557120760 is an apocalyptic number.

261557120760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261557120760 is an abundant number, since it is smaller than the sum of its proper divisors (583473582120).

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

261557120760 is a wasteful number, since it uses less digits than its factorization.

261557120760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167664848 (or 167664844 counting only the distinct ones).

The product of its (nonzero) digits is 176400, while the sum is 42.

The spelling of 261557120760 in words is "two hundred sixty-one billion, five hundred fifty-seven million, one hundred twenty thousand, seven hundred sixty".