21153841 has 2 divisors, whose sum is σ = 21153842. Its totient is φ = 21153840.

The previous prime is 21153829. The next prime is 21153851. The reversal of 21153841 is 14835112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21123216 + 30625 = 4596^2 + 175^2 .

It is a cyclic number.

It is not a de Polignac number, because 21153841 - 2⁵ = 21153809 is a prime.

It is not a weakly prime, because it can be changed into another prime (21153851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10576920 + 10576921.

It is an arithmetic number, because the mean of its divisors is an integer number (10576921).

Almost surely, 2^21153841 is an apocalyptic number.

It is an amenable number.

21153841 is a deficient number, since it is larger than the sum of its proper divisors (1).

21153841 is an equidigital number, since it uses as much as digits as its factorization.

21153841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 25.

The square root of 21153841 is about 4599.3304947568. The cubic root of 21153841 is about 276.5644865488.

Adding to 21153841 its reverse (14835112), we get a palindrome (35988953).

The spelling of 21153841 in words is "twenty-one million, one hundred fifty-three thousand, eight hundred forty-one".