21894355332533 has 2 divisors, whose sum is σ = 21894355332534. Its totient is φ = 21894355332532.

The previous prime is 21894355332503. The next prime is 21894355332617. The reversal of 21894355332533 is 33523355349812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17596288312849 + 4298067019684 = 4194793^2 + 2073178^2 .

It is a cyclic number.

It is not a de Polignac number, because 21894355332533 - 2¹⁶ = 21894355266997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21894355332503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10947177666266 + 10947177666267.

It is an arithmetic number, because the mean of its divisors is an integer number (10947177666267).

Almost surely, 2^{21894355332533} is an apocalyptic number.

It is an amenable number.

21894355332533 is a deficient number, since it is larger than the sum of its proper divisors (1).

21894355332533 is an equidigital number, since it uses as much as digits as its factorization.

21894355332533 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992000, while the sum is 56.

The spelling of 21894355332533 in words is "twenty-one trillion, eight hundred ninety-four billion, three hundred fifty-five million, three hundred thirty-two thousand, five hundred thirty-three".