10991305220 has 24 divisors (see below), whose sum is σ = 26379132864. Its totient is φ = 3768447456.

The previous prime is 10991305187. The next prime is 10991305243. The reversal of 10991305220 is 2250319901.

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, 39254522 + ... + 39254801.

It is an arithmetic number, because the mean of its divisors is an integer number (1099130536).

Almost surely, 2^10991305220 is an apocalyptic number.

10991305220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

10991305220 is an abundant number, since it is smaller than the sum of its proper divisors (15387827644).

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

10991305220 is a wasteful number, since it uses less digits than its factorization.

10991305220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78509339 (or 78509337 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 32.

The spelling of 10991305220 in words is "ten billion, nine hundred ninety-one million, three hundred five thousand, two hundred twenty".