21851153 has 2 divisors, whose sum is σ = 21851154. Its totient is φ = 21851152.

The previous prime is 21851119. The next prime is 21851177. The reversal of 21851153 is 35115812.

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., 21743569 + 107584 = 4663^2 + 328^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21851153 is a prime.

It is not a weakly prime, because it can be changed into another prime (21851113) 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, 10925576 + 10925577.

It is an arithmetic number, because the mean of its divisors is an integer number (10925577).

Almost surely, 2^21851153 is an apocalyptic number.

It is an amenable number.

21851153 is a deficient number, since it is larger than the sum of its proper divisors (1).

21851153 is an equidigital number, since it uses as much as digits as its factorization.

21851153 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1200, while the sum is 26.

The square root of 21851153 is about 4674.5216867611. The cubic root of 21851153 is about 279.5705704721.

Adding to 21851153 its reverse (35115812), we get a palindrome (56966965).

The spelling of 21851153 in words is "twenty-one million, eight hundred fifty-one thousand, one hundred fifty-three".