261310809460 has 24 divisors (see below), whose sum is σ = 551107871496. Its totient is φ = 104075719680.

The previous prime is 261310809449. The next prime is 261310809497. The reversal of 261310809460 is 64908013162.

It can be written as a sum of positive squares in 4 ways, for example, as 64838473956 + 196472335504 = 254634^2 + 443252^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28032981 + ... + 28042300.

It is an arithmetic number, because the mean of its divisors is an integer number (22962827979).

Almost surely, 2^261310809460 is an apocalyptic number.

261310809460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261310809460 is an abundant number, since it is smaller than the sum of its proper divisors (289797062036).

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

261310809460 is a wasteful number, since it uses less digits than its factorization.

261310809460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56075523 (or 56075521 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 40.

The spelling of 261310809460 in words is "two hundred sixty-one billion, three hundred ten million, eight hundred nine thousand, four hundred sixty".