21450205233493 has 2 divisors, whose sum is σ = 21450205233494. Its totient is φ = 21450205233492.

The previous prime is 21450205233397. The next prime is 21450205233503. The reversal of 21450205233493 is 39433250205412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12246129305809 + 9204075927684 = 3499447^2 + 3033822^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21450205233493 is a prime.

It is a super-2 number, since 2×21450205233493² (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 (21450205239493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10725102616746 + 10725102616747.

It is an arithmetic number, because the mean of its divisors is an integer number (10725102616747).

Almost surely, 2^{21450205233493} is an apocalyptic number.

It is an amenable number.

21450205233493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21450205233493 is an equidigital number, since it uses as much as digits as its factorization.

21450205233493 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 777600, while the sum is 43.

The spelling of 21450205233493 in words is "twenty-one trillion, four hundred fifty billion, two hundred five million, two hundred thirty-three thousand, four hundred ninety-three".