261920991596 has 48 divisors (see below), whose sum is σ = 503637523200. Its totient is φ = 118197097920.

The previous prime is 261920991581. The next prime is 261920991617. The reversal of 261920991596 is 695199029162.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14853641 + ... + 14871263.

It is an arithmetic number, because the mean of its divisors is an integer number (10492448400).

Almost surely, 2^261920991596 is an apocalyptic number.

It is an amenable number.

261920991596 is a deficient number, since it is larger than the sum of its proper divisors (241716531604).

261920991596 is a wasteful number, since it uses less digits than its factorization.

261920991596 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20054 (or 20052 counting only the distinct ones).

The product of its (nonzero) digits is 4723920, while the sum is 59.

The spelling of 261920991596 in words is "two hundred sixty-one billion, nine hundred twenty million, nine hundred ninety-one thousand, five hundred ninety-six".