21717601447 has 2 divisors, whose sum is σ = 21717601448. Its totient is φ = 21717601446.

The previous prime is 21717601441. The next prime is 21717601453. The reversal of 21717601447 is 74410671712.

It is a balanced prime because it is at equal distance from previous prime (21717601441) and next prime (21717601453).

It is a cyclic number.

It is not a de Polignac number, because 21717601447 - 2⁷ = 21717601319 is a prime.

It is a super-4 number, since 4×21717601447⁴ (a number of 42 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21717601441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10858800723 + 10858800724.

It is an arithmetic number, because the mean of its divisors is an integer number (10858800724).

Almost surely, 2^21717601447 is an apocalyptic number.

21717601447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21717601447 is an equidigital number, since it uses as much as digits as its factorization.

21717601447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 65856, while the sum is 40.

The spelling of 21717601447 in words is "twenty-one billion, seven hundred seventeen million, six hundred one thousand, four hundred forty-seven".