261302815956 has 96 divisors (see below), whose sum is σ = 752338379520. Its totient is φ = 68737757184.

The previous prime is 261302815937. The next prime is 261302816009. The reversal of 261302815956 is 659518203162.

It is a congruent number.

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, 117220 + ... + 732356.

It is an arithmetic number, because the mean of its divisors is an integer number (7836858120).

Almost surely, 2^261302815956 is an apocalyptic number.

261302815956 is a gapful number since it is divisible by the number (26) 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 261302815956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (376169189760).

261302815956 is an abundant number, since it is smaller than the sum of its proper divisors (491035563564).

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

261302815956 is a wasteful number, since it uses less digits than its factorization.

261302815956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615553 (or 615551 counting only the distinct ones).

The product of its (nonzero) digits is 777600, while the sum is 48.

The spelling of 261302815956 in words is "two hundred sixty-one billion, three hundred two million, eight hundred fifteen thousand, nine hundred fifty-six".