10991358563920 has 240 divisors, whose sum is σ = 31566049174800. Its totient is φ = 3536621125632.

The previous prime is 10991358563897. The next prime is 10991358563923. The reversal of 10991358563920 is 2936585319901.

It can be written as a sum of positive squares in 8 ways, for example, as 2114558039104 + 8876800524816 = 1454152^2 + 2979396^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10991358563923) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23021062 + ... + 23493658.

It is an arithmetic number, because the mean of its divisors is an integer number (131525204895).

Almost surely, 2^{10991358563920} is an apocalyptic number.

10991358563920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 10991358563920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15783024587400).

10991358563920 is an abundant number, since it is smaller than the sum of its proper divisors (20574690610880).

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

10991358563920 is a wasteful number, since it uses less digits than its factorization.

10991358563920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472990 (or 472977 counting only the distinct ones).

The product of its (nonzero) digits is 15746400, while the sum is 61.

The spelling of 10991358563920 in words is "ten trillion, nine hundred ninety-one billion, three hundred fifty-eight million, five hundred sixty-three thousand, nine hundred twenty".