11857820 has 48 divisors (see below), whose sum is σ = 27306720. Its totient is φ = 4298496.

The previous prime is 11857819. The next prime is 11857831. The reversal of 11857820 is 2875811.

It is a happy number.

It is a super-3 number, since 3×11857820³ (a number of 22 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14954 + ... + 15726.

It is an arithmetic number, because the mean of its divisors is an integer number (568890).

Almost surely, 2^11857820 is an apocalyptic number.

11857820 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 11857820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13653360).

11857820 is an abundant number, since it is smaller than the sum of its proper divisors (15448900).

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

11857820 is a wasteful number, since it uses less digits than its factorization.

11857820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 854 (or 852 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 11857820 is about 3443.5185493910. The cubic root of 11857820 is about 228.0350566799.

Subtracting from 11857820 its reverse (2875811), we obtain a square (8982009 = 2997²).

The spelling of 11857820 in words is "eleven million, eight hundred fifty-seven thousand, eight hundred twenty".