10991220810 has 64 divisors (see below), whose sum is σ = 27248569344. Its totient is φ = 2834496000.

The previous prime is 10991220797. The next prime is 10991220811. The reversal of 10991220810 is 1802219901.

It is a super-2 number, since 2×10991220810² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (10991220811) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1764822 + ... + 1771038.

It is an arithmetic number, because the mean of its divisors is an integer number (425758896).

Almost surely, 2^10991220810 is an apocalyptic number.

10991220810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 10991220810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13624284672).

10991220810 is an abundant number, since it is smaller than the sum of its proper divisors (16257348534).

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

10991220810 is a wasteful number, since it uses less digits than its factorization.

10991220810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8159.

The product of its (nonzero) digits is 2592, while the sum is 33.

The spelling of 10991220810 in words is "ten billion, nine hundred ninety-one million, two hundred twenty thousand, eight hundred ten".