261161263616 has 80 divisors (see below), whose sum is σ = 599210710560. Its totient is φ = 112461742080.

The previous prime is 261161263579. The next prime is 261161263633. The reversal of 261161263616 is 616362161162.

It is a super-2 number, since 2×261161263616² (a number of 24 digits) contains 22 as substring.

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, 1113281 + ... + 1327296.

It is an arithmetic number, because the mean of its divisors is an integer number (7490133882).

Almost surely, 2^261161263616 is an apocalyptic number.

It is an amenable number.

261161263616 is an abundant number, since it is smaller than the sum of its proper divisors (338049446944).

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

261161263616 is a wasteful number, since it uses less digits than its factorization.

261161263616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2440625 (or 2440609 counting only the distinct ones).

The product of its digits is 93312, while the sum is 41.

The spelling of 261161263616 in words is "two hundred sixty-one billion, one hundred sixty-one million, two hundred sixty-three thousand, six hundred sixteen".