261603346518 has 64 divisors (see below), whose sum is σ = 586856529600. Its totient is φ = 86374252800.

The previous prime is 261603346481. The next prime is 261603346577. The reversal of 261603346518 is 815643306162.

261603346518 is a `hidden beast` number, since 2 + 6 + 1 + 60 + 33 + 46 + 518 = 666.

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, 30020130 + ... + 30028842.

It is an arithmetic number, because the mean of its divisors is an integer number (9169633275).

Almost surely, 2^261603346518 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261603346518, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (293428264800).

261603346518 is an abundant number, since it is smaller than the sum of its proper divisors (325253183082).

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

261603346518 is a wasteful number, since it uses less digits than its factorization.

261603346518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13934 (or 13928 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 261603346518 in words is "two hundred sixty-one billion, six hundred three million, three hundred forty-six thousand, five hundred eighteen".