261421056351125 has 128 divisors (see below), whose sum is σ = 378741668977152. Its totient is φ = 178042368000000.

The previous prime is 261421056351121. The next prime is 261421056351149. The reversal of 261421056351125 is 521153650124162.

It is a happy number.

It is not a de Polignac number, because 261421056351125 - 2² = 261421056351121 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261421056351121) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 28611252557 + ... + 28611261693.

It is an arithmetic number, because the mean of its divisors is an integer number (2958919288884).

Almost surely, 2^{261421056351125} is an apocalyptic number.

261421056351125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261421056351125 is a deficient number, since it is larger than the sum of its proper divisors (117320612626027).

261421056351125 is a wasteful number, since it uses less digits than its factorization.

261421056351125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15192 (or 15182 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 44.

The spelling of 261421056351125 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, fifty-six million, three hundred fifty-one thousand, one hundred twenty-five".