21732656417 has 2 divisors, whose sum is σ = 21732656418. Its totient is φ = 21732656416.

The previous prime is 21732656383. The next prime is 21732656419. The reversal of 21732656417 is 71465623712.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16096250641 + 5636405776 = 126871^2 + 75076^2 .

It is a cyclic number.

It is not a de Polignac number, because 21732656417 - 2⁶ = 21732656353 is a prime.

Together with 21732656419, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21732656419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10866328208 + 10866328209.

It is an arithmetic number, because the mean of its divisors is an integer number (10866328209).

Almost surely, 2^21732656417 is an apocalyptic number.

It is an amenable number.

21732656417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21732656417 is an equidigital number, since it uses as much as digits as its factorization.

21732656417 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 423360, while the sum is 44.

The spelling of 21732656417 in words is "twenty-one billion, seven hundred thirty-two million, six hundred fifty-six thousand, four hundred seventeen".