11821851 has 12 divisors (see below), whose sum is σ = 18080712. Its totient is φ = 7417536.

The previous prime is 11821847. The next prime is 11821853. The reversal of 11821851 is 15812811.

11821851 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11821851 - 2² = 11821847 is a prime.

It is a super-2 number, since 2×11821851² = 279512322132402, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11821853) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38481 + ... + 38786.

It is an arithmetic number, because the mean of its divisors is an integer number (1506726).

Almost surely, 2^11821851 is an apocalyptic number.

11821851 is a deficient number, since it is larger than the sum of its proper divisors (6258861).

11821851 is a wasteful number, since it uses less digits than its factorization.

11821851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77290 (or 77287 counting only the distinct ones).

The product of its digits is 640, while the sum is 27.

The square root of 11821851 is about 3438.2918724274. The cubic root of 11821851 is about 227.8042525818.

The spelling of 11821851 in words is "eleven million, eight hundred twenty-one thousand, eight hundred fifty-one".