21421323533 has 2 divisors, whose sum is σ = 21421323534. Its totient is φ = 21421323532.

The previous prime is 21421323529. The next prime is 21421323611. The reversal of 21421323533 is 33532312412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21410420329 + 10903204 = 146323^2 + 3302^2 .

It is a cyclic number.

It is not a de Polignac number, because 21421323533 - 2² = 21421323529 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21421323496 and 21421323505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21421323503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710661766 + 10710661767.

It is an arithmetic number, because the mean of its divisors is an integer number (10710661767).

Almost surely, 2^21421323533 is an apocalyptic number.

It is an amenable number.

21421323533 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421323533 is an equidigital number, since it uses as much as digits as its factorization.

21421323533 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 29.

Adding to 21421323533 its reverse (33532312412), we get a palindrome (54953635945).

The spelling of 21421323533 in words is "twenty-one billion, four hundred twenty-one million, three hundred twenty-three thousand, five hundred thirty-three".