11851820 has 24 divisors (see below), whose sum is σ = 26199600. Its totient is φ = 4491072.

The previous prime is 11851813. The next prime is 11851841. The reversal of 11851820 is 2815811.

It is a self number, because there is not a number n which added to its sum of digits gives 11851820.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15215 + ... + 15974.

It is an arithmetic number, because the mean of its divisors is an integer number (1091650).

Almost surely, 2^11851820 is an apocalyptic number.

11851820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11851820 is an abundant number, since it is smaller than the sum of its proper divisors (14347780).

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

11851820 is a wasteful number, since it uses less digits than its factorization.

11851820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31217 (or 31215 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 26.

The square root of 11851820 is about 3442.6472372289. The cubic root of 11851820 is about 227.9965886429.

The spelling of 11851820 in words is "eleven million, eight hundred fifty-one thousand, eight hundred twenty".