261299709580 has 96 divisors (see below), whose sum is σ = 676145885184. Its totient is φ = 82600729344.

The previous prime is 261299709571. The next prime is 261299709611. The reversal of 261299709580 is 85907992162.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1487479 + ... + 1653841.

It is an arithmetic number, because the mean of its divisors is an integer number (7043186304).

Almost surely, 2^261299709580 is an apocalyptic number.

261299709580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261299709580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (338072942592).

261299709580 is an abundant number, since it is smaller than the sum of its proper divisors (414846175604).

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

261299709580 is a wasteful number, since it uses less digits than its factorization.

261299709580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167255 (or 167253 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 58.

The spelling of 261299709580 in words is "two hundred sixty-one billion, two hundred ninety-nine million, seven hundred nine thousand, five hundred eighty".