21430752017 has 2 divisors, whose sum is σ = 21430752018. Its totient is φ = 21430752016.

The previous prime is 21430751999. The next prime is 21430752019. The reversal of 21430752017 is 71025703412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17670119041 + 3760632976 = 132929^2 + 61324^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21430752017 is a prime.

It is a super-3 number, since 3×21430752017³ (a number of 32 digits) contains 333 as substring.

Together with 21430752019, 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 (21430752019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715376008 + 10715376009.

It is an arithmetic number, because the mean of its divisors is an integer number (10715376009).

Almost surely, 2^21430752017 is an apocalyptic number.

It is an amenable number.

21430752017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21430752017 is an equidigital number, since it uses as much as digits as its factorization.

21430752017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11760, while the sum is 32.

The spelling of 21430752017 in words is "twenty-one billion, four hundred thirty million, seven hundred fifty-two thousand, seventeen".