21006326633 has 2 divisors, whose sum is σ = 21006326634. Its totient is φ = 21006326632.

The previous prime is 21006326599. The next prime is 21006326681. The reversal of 21006326633 is 33662360012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16680239104 + 4326087529 = 129152^2 + 65773^2 .

It is a cyclic number.

It is not a de Polignac number, because 21006326633 - 2¹⁸ = 21006064489 is a prime.

It is a super-2 number, since 2×21006326633² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21006326633.

It is not a weakly prime, because it can be changed into another prime (21006326533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10503163316 + 10503163317.

It is an arithmetic number, because the mean of its divisors is an integer number (10503163317).

Almost surely, 2^21006326633 is an apocalyptic number.

It is an amenable number.

21006326633 is a deficient number, since it is larger than the sum of its proper divisors (1).

21006326633 is an equidigital number, since it uses as much as digits as its factorization.

21006326633 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 32.

Adding to 21006326633 its reverse (33662360012), we get a palindrome (54668686645).

The spelling of 21006326633 in words is "twenty-one billion, six million, three hundred twenty-six thousand, six hundred thirty-three".