21354664722473 has 2 divisors, whose sum is σ = 21354664722474. Its totient is φ = 21354664722472.

The previous prime is 21354664722407. The next prime is 21354664722481. The reversal of 21354664722473 is 37422746645312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21262353876544 + 92310845929 = 4611112^2 + 303827^2 .

It is a cyclic number.

It is not a de Polignac number, because 21354664722473 - 2³² = 21350369755177 is a prime.

It is a super-2 number, since 2×21354664722473² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21354664722403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10677332361236 + 10677332361237.

It is an arithmetic number, because the mean of its divisors is an integer number (10677332361237).

Almost surely, 2^{21354664722473} is an apocalyptic number.

It is an amenable number.

21354664722473 is a deficient number, since it is larger than the sum of its proper divisors (1).

21354664722473 is an equidigital number, since it uses as much as digits as its factorization.

21354664722473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40642560, while the sum is 56.

The spelling of 21354664722473 in words is "twenty-one trillion, three hundred fifty-four billion, six hundred sixty-four million, seven hundred twenty-two thousand, four hundred seventy-three".