21032331217 has 2 divisors, whose sum is σ = 21032331218. Its totient is φ = 21032331216.

The previous prime is 21032331191. The next prime is 21032331227. The reversal of 21032331217 is 71213323012.

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., 20191273216 + 841058001 = 142096^2 + 29001^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21032331217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21032331191 and 21032331200.

It is not a weakly prime, because it can be changed into another prime (21032331227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10516165608 + 10516165609.

It is an arithmetic number, because the mean of its divisors is an integer number (10516165609).

Almost surely, 2^21032331217 is an apocalyptic number.

It is an amenable number.

21032331217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21032331217 is an equidigital number, since it uses as much as digits as its factorization.

21032331217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 25.

Adding to 21032331217 its reverse (71213323012), we get a palindrome (92245654229).

The spelling of 21032331217 in words is "twenty-one billion, thirty-two million, three hundred thirty-one thousand, two hundred seventeen".