21489833 has 2 divisors, whose sum is σ = 21489834. Its totient is φ = 21489832.

The previous prime is 21489829. The next prime is 21489877. The reversal of 21489833 is 33898412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20720704 + 769129 = 4552^2 + 877^2 .

It is a cyclic number.

It is not a de Polignac number, because 21489833 - 2² = 21489829 is a prime.

It is not a weakly prime, because it can be changed into another prime (21489803) 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, 10744916 + 10744917.

It is an arithmetic number, because the mean of its divisors is an integer number (10744917).

Almost surely, 2^21489833 is an apocalyptic number.

It is an amenable number.

21489833 is a deficient number, since it is larger than the sum of its proper divisors (1).

21489833 is an equidigital number, since it uses as much as digits as its factorization.

21489833 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 38.

The square root of 21489833 is about 4635.7127823022. The cubic root of 21489833 is about 278.0210506289.

It can be divided in two parts, 21489 and 833, that added together give a palindrome (22322).

The spelling of 21489833 in words is "twenty-one million, four hundred eighty-nine thousand, eight hundred thirty-three".