21659444533 has 2 divisors, whose sum is σ = 21659444534. Its totient is φ = 21659444532.

The previous prime is 21659444531. The next prime is 21659444551. The reversal of 21659444533 is 33544495612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17450938404 + 4208506129 = 132102^2 + 64873^2 .

It is a cyclic number.

It is not a de Polignac number, because 21659444533 - 2¹ = 21659444531 is a prime.

Together with 21659444531, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21659444531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10829722266 + 10829722267.

It is an arithmetic number, because the mean of its divisors is an integer number (10829722267).

Almost surely, 2^21659444533 is an apocalyptic number.

It is an amenable number.

21659444533 is a deficient number, since it is larger than the sum of its proper divisors (1).

21659444533 is an equidigital number, since it uses as much as digits as its factorization.

21659444533 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1555200, while the sum is 46.

The spelling of 21659444533 in words is "twenty-one billion, six hundred fifty-nine million, four hundred forty-four thousand, five hundred thirty-three".