11655821 has 2 divisors, whose sum is σ = 11655822. Its totient is φ = 11655820.

The previous prime is 11655817. The next prime is 11655827. The reversal of 11655821 is 12855611.

11655821 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7896100 + 3759721 = 2810^2 + 1939^2 .

It is a cyclic number.

It is not a de Polignac number, because 11655821 - 2² = 11655817 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11655827) 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 as a sum of consecutive naturals, namely, 5827910 + 5827911.

It is an arithmetic number, because the mean of its divisors is an integer number (5827911).

Almost surely, 2^11655821 is an apocalyptic number.

It is an amenable number.

11655821 is a deficient number, since it is larger than the sum of its proper divisors (1).

11655821 is an equidigital number, since it uses as much as digits as its factorization.

11655821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 29.

The square root of 11655821 is about 3414.0622431350. The cubic root of 11655821 is about 226.7327678707.

The spelling of 11655821 in words is "eleven million, six hundred fifty-five thousand, eight hundred twenty-one".