11821280 has 24 divisors (see below), whose sum is σ = 27928152. Its totient is φ = 4728448.

The previous prime is 11821267. The next prime is 11821283. The reversal of 11821280 is 8212811.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11821283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36782 + ... + 37101.

It is an arithmetic number, because the mean of its divisors is an integer number (1163673).

Almost surely, 2^11821280 is an apocalyptic number.

11821280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11821280 is an abundant number, since it is smaller than the sum of its proper divisors (16106872).

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

11821280 is an equidigital number, since it uses as much as digits as its factorization.

11821280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73898 (or 73890 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 23.

The square root of 11821280 is about 3438.2088360075. The cubic root of 11821280 is about 227.8005848448.

It can be divided in two parts, 1 and 1821280, that added together give a palindrome (1821281).

The spelling of 11821280 in words is "eleven million, eight hundred twenty-one thousand, two hundred eighty".