21534053454253 has 2 divisors, whose sum is σ = 21534053454254. Its totient is φ = 21534053454252.

The previous prime is 21534053454229. The next prime is 21534053454259. The reversal of 21534053454253 is 35245435043512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14548747175524 + 6985306278729 = 3814282^2 + 2642973^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21534053454253 is a prime.

It is a super-2 number, since 2×21534053454253² (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 (21534053454259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10767026727126 + 10767026727127.

It is an arithmetic number, because the mean of its divisors is an integer number (10767026727127).

Almost surely, 2^{21534053454253} is an apocalyptic number.

It is an amenable number.

21534053454253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21534053454253 is an equidigital number, since it uses as much as digits as its factorization.

21534053454253 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320000, while the sum is 46.

Adding to 21534053454253 its reverse (35245435043512), we get a palindrome (56779488497765).

The spelling of 21534053454253 in words is "twenty-one trillion, five hundred thirty-four billion, fifty-three million, four hundred fifty-four thousand, two hundred fifty-three".