21861065333 has 2 divisors, whose sum is σ = 21861065334. Its totient is φ = 21861065332.

The previous prime is 21861065321. The next prime is 21861065351. The reversal of 21861065333 is 33356016812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14966586244 + 6894479089 = 122338^2 + 83033^2 .

It is a cyclic number.

It is not a de Polignac number, because 21861065333 - 2⁸ = 21861065077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21861065393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10930532666 + 10930532667.

It is an arithmetic number, because the mean of its divisors is an integer number (10930532667).

Almost surely, 2^21861065333 is an apocalyptic number.

It is an amenable number.

21861065333 is a deficient number, since it is larger than the sum of its proper divisors (1).

21861065333 is an equidigital number, since it uses as much as digits as its factorization.

21861065333 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 38.

The spelling of 21861065333 in words is "twenty-one billion, eight hundred sixty-one million, sixty-five thousand, three hundred thirty-three".