21490033 has 2 divisors, whose sum is σ = 21490034. Its totient is φ = 21490032.

The previous prime is 21490031. The next prime is 21490043. The reversal of 21490033 is 33009412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21095649 + 394384 = 4593^2 + 628^2 .

It is a cyclic number.

It is not a de Polignac number, because 21490033 - 2¹ = 21490031 is a prime.

Together with 21490031, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21489986 and 21490013.

It is not a weakly prime, because it can be changed into another prime (21490031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10745016 + 10745017.

It is an arithmetic number, because the mean of its divisors is an integer number (10745017).

Almost surely, 2^21490033 is an apocalyptic number.

It is an amenable number.

21490033 is a deficient number, since it is larger than the sum of its proper divisors (1).

21490033 is an equidigital number, since it uses as much as digits as its factorization.

21490033 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 21490033 is about 4635.7343539077. The cubic root of 21490033 is about 278.0219131149.

Adding to 21490033 its reverse (33009412), we get a palindrome (54499445).

The spelling of 21490033 in words is "twenty-one million, four hundred ninety thousand, thirty-three".