21152441 has 2 divisors, whose sum is σ = 21152442. Its totient is φ = 21152440.

The previous prime is 21152423. The next prime is 21152449. The reversal of 21152441 is 14425112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21114025 + 38416 = 4595^2 + 196^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21152441 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21152449) 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, 10576220 + 10576221.

It is an arithmetic number, because the mean of its divisors is an integer number (10576221).

Almost surely, 2^21152441 is an apocalyptic number.

It is an amenable number.

21152441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21152441 is an equidigital number, since it uses as much as digits as its factorization.

21152441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 320, while the sum is 20.

The square root of 21152441 is about 4599.1782961742. The cubic root of 21152441 is about 276.5583852325.

Adding to 21152441 its reverse (14425112), we get a palindrome (35577553).

The spelling of 21152441 in words is "twenty-one million, one hundred fifty-two thousand, four hundred forty-one".