21354664722793 has 2 divisors, whose sum is σ = 21354664722794. Its totient is φ = 21354664722792.

The previous prime is 21354664722761. The next prime is 21354664722841. The reversal of 21354664722793 is 39722746645312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21166228858329 + 188435864464 = 4600677^2 + 434092^2 .

It is a cyclic number.

It is not a de Polignac number, because 21354664722793 - 2⁵ = 21354664722761 is a prime.

It is not a weakly prime, because it can be changed into another prime (21354664752793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10677332361396 + 10677332361397.

It is an arithmetic number, because the mean of its divisors is an integer number (10677332361397).

Almost surely, 2^{21354664722793} is an apocalyptic number.

It is an amenable number.

21354664722793 is a deficient number, since it is larger than the sum of its proper divisors (1).

21354664722793 is an equidigital number, since it uses as much as digits as its factorization.

21354664722793 is an evil number, because the sum of its binary digits is even.

The product of its digits is 91445760, while the sum is 61.

The spelling of 21354664722793 in words is "twenty-one trillion, three hundred fifty-four billion, six hundred sixty-four million, seven hundred twenty-two thousand, seven hundred ninety-three".