261568642388 has 24 divisors (see below), whose sum is σ = 482507222400. Its totient is φ = 123728586048.

The previous prime is 261568642373. The next prime is 261568642421. The reversal of 261568642388 is 883246865162.

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, 2338745 + ... + 2448032.

It is an arithmetic number, because the mean of its divisors is an integer number (20104467600).

Almost surely, 2^261568642388 is an apocalyptic number.

It is an amenable number.

261568642388 is a deficient number, since it is larger than the sum of its proper divisors (220938580012).

261568642388 is a wasteful number, since it uses less digits than its factorization.

261568642388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4787519 (or 4787517 counting only the distinct ones).

The product of its digits is 26542080, while the sum is 59.

The spelling of 261568642388 in words is "two hundred sixty-one billion, five hundred sixty-eight million, six hundred forty-two thousand, three hundred eighty-eight".