21031002003217 has 2 divisors, whose sum is σ = 21031002003218. Its totient is φ = 21031002003216.

The previous prime is 21031002003197. The next prime is 21031002003227. The reversal of 21031002003217 is 71230020013012.

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., 17534285260816 + 3496716742401 = 4187396^2 + 1869951^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21031002003217 is a prime.

It is not a weakly prime, because it can be changed into another prime (21031002003227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515501001608 + 10515501001609.

It is an arithmetic number, because the mean of its divisors is an integer number (10515501001609).

Almost surely, 2^{21031002003217} is an apocalyptic number.

It is an amenable number.

21031002003217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031002003217 is an equidigital number, since it uses as much as digits as its factorization.

21031002003217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 22.

Adding to 21031002003217 its reverse (71230020013012), we get a palindrome (92261022016229).

The spelling of 21031002003217 in words is "twenty-one trillion, thirty-one billion, two million, three thousand, two hundred seventeen".