21183121 has 2 divisors, whose sum is σ = 21183122. Its totient is φ = 21183120.

The previous prime is 21183109. The next prime is 21183167. The reversal of 21183121 is 12138112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15249025 + 5934096 = 3905^2 + 2436^2 .

It is a cyclic number.

It is not a de Polignac number, because 21183121 - 2⁵ = 21183089 is a prime.

It is equal to p_1340803 and since 21183121 and 1340803 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21183521) by changing a digit.

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 as a sum of consecutive naturals, namely, 10591560 + 10591561.

It is an arithmetic number, because the mean of its divisors is an integer number (10591561).

Almost surely, 2^21183121 is an apocalyptic number.

It is an amenable number.

21183121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21183121 is an equidigital number, since it uses as much as digits as its factorization.

21183121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96, while the sum is 19.

The square root of 21183121 is about 4602.5124660342. The cubic root of 21183121 is about 276.6920295775.

The spelling of 21183121 in words is "twenty-one million, one hundred eighty-three thousand, one hundred twenty-one".