11801920 has 56 divisors (see below), whose sum is σ = 30275784. Its totient is φ = 4356096.

The previous prime is 11801899. The next prime is 11801939. The reversal of 11801920 is 2910811.

It can be written as a sum of positive squares in 4 ways, for example, as 350464 + 11451456 = 592^2 + 3384^2 .

It is a junction number, because it is equal to n+sod(n) for n = 11801891 and 11801900.

It is a congruent number.

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, 2742 + ... + 5578.

It is an arithmetic number, because the mean of its divisors is an integer number (540639).

Almost surely, 2^11801920 is an apocalyptic number.

11801920 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 11801920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15137892).

11801920 is an abundant number, since it is smaller than the sum of its proper divisors (18473864).

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

11801920 is a wasteful number, since it uses less digits than its factorization.

11801920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2867 (or 2857 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 11801920 is about 3435.3922629010. The cubic root of 11801920 is about 227.6761586943.

It can be divided in two parts, 11801 and 920, that added together give a palindrome (12721).

The spelling of 11801920 in words is "eleven million, eight hundred one thousand, nine hundred twenty".