21213244433 has 2 divisors, whose sum is σ = 21213244434. Its totient is φ = 21213244432.

The previous prime is 21213244427. The next prime is 21213244489. The reversal of 21213244433 is 33444231212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16267216849 + 4946027584 = 127543^2 + 70328^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213244433 - 2⁶ = 21213244369 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21213244396 and 21213244405.

It is not a weakly prime, because it can be changed into another prime (21213241433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606622216 + 10606622217.

It is an arithmetic number, because the mean of its divisors is an integer number (10606622217).

Almost surely, 2^21213244433 is an apocalyptic number.

It is an amenable number.

21213244433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213244433 is an equidigital number, since it uses as much as digits as its factorization.

21213244433 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 29.

Adding to 21213244433 its reverse (33444231212), we get a palindrome (54657475645).

The spelling of 21213244433 in words is "twenty-one billion, two hundred thirteen million, two hundred forty-four thousand, four hundred thirty-three".