21213602033381 has 2 divisors, whose sum is σ = 21213602033382. Its totient is φ = 21213602033380.

The previous prime is 21213602033333. The next prime is 21213602033489. The reversal of 21213602033381 is 18333020631212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20890466630881 + 323135402500 = 4570609^2 + 568450^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21213602033381 is a prime.

It is a super-2 number, since 2×21213602033381² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21213602033311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606801016690 + 10606801016691.

It is an arithmetic number, because the mean of its divisors is an integer number (10606801016691).

Almost surely, 2^{21213602033381} is an apocalyptic number.

It is an amenable number.

21213602033381 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213602033381 is an equidigital number, since it uses as much as digits as its factorization.

21213602033381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 35.

Adding to 21213602033381 its reverse (18333020631212), we get a palindrome (39546622664593).

The spelling of 21213602033381 in words is "twenty-one trillion, two hundred thirteen billion, six hundred two million, thirty-three thousand, three hundred eighty-one".