21533454355253 has 2 divisors, whose sum is σ = 21533454355254. Its totient is φ = 21533454355252.

The previous prime is 21533454355249. The next prime is 21533454355327. The reversal of 21533454355253 is 35255345433512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20859516797284 + 673937557969 = 4567222^2 + 820937^2 .

It is a cyclic number.

It is not a de Polignac number, because 21533454355253 - 2² = 21533454355249 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21533454355213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766727177626 + 10766727177627.

It is an arithmetic number, because the mean of its divisors is an integer number (10766727177627).

Almost surely, 2^{21533454355253} is an apocalyptic number.

It is an amenable number.

21533454355253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21533454355253 is an equidigital number, since it uses as much as digits as its factorization.

21533454355253 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16200000, while the sum is 50.

Adding to 21533454355253 its reverse (35255345433512), we get a palindrome (56788799788765).

The spelling of 21533454355253 in words is "twenty-one trillion, five hundred thirty-three billion, four hundred fifty-four million, three hundred fifty-five thousand, two hundred fifty-three".