21517224943 has 2 divisors, whose sum is σ = 21517224944. Its totient is φ = 21517224942.

The previous prime is 21517224929. The next prime is 21517225001. The reversal of 21517224943 is 34942271512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21517224943 - 2²⁵ = 21483670511 is a prime.

It is a super-2 number, since 2×21517224943² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21517224896 and 21517224905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21517222943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10758612471 + 10758612472.

It is an arithmetic number, because the mean of its divisors is an integer number (10758612472).

Almost surely, 2^21517224943 is an apocalyptic number.

21517224943 is a deficient number, since it is larger than the sum of its proper divisors (1).

21517224943 is an equidigital number, since it uses as much as digits as its factorization.

21517224943 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 40.

The spelling of 21517224943 in words is "twenty-one billion, five hundred seventeen million, two hundred twenty-four thousand, nine hundred forty-three".