11981020 has 48 divisors (see below), whose sum is σ = 27165600. Its totient is φ = 4423680.

The previous prime is 11981017. The next prime is 11981023. The reversal of 11981020 is 2018911.

It is an interprime number because it is at equal distance from previous prime (11981017) and next prime (11981023).

It is a junction number, because it is equal to n+sod(n) for n = 11980982 and 11981000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11981023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15196 + ... + 15964.

It is an arithmetic number, because the mean of its divisors is an integer number (565950).

Almost surely, 2^11981020 is an apocalyptic number.

11981020 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 11981020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13582800).

11981020 is an abundant number, since it is smaller than the sum of its proper divisors (15184580).

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

11981020 is a wasteful number, since it uses less digits than its factorization.

11981020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 838 (or 836 counting only the distinct ones).

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

The square root of 11981020 is about 3461.3610039983. The cubic root of 11981020 is about 228.8220810596.

Adding to 11981020 its reverse (2018911), we get a palindrome (13999931).

The spelling of 11981020 in words is "eleven million, nine hundred eighty-one thousand, twenty".