321891504217 has 2 divisors, whose sum is σ = 321891504218. Its totient is φ = 321891504216.

The previous prime is 321891504199. The next prime is 321891504227. The reversal of 321891504217 is 712405198123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 251541368521 + 70350135696 = 501539^2 + 265236^2 .

It is a cyclic number.

It is not a de Polignac number, because 321891504217 - 2¹⁹ = 321890979929 is a prime.

It is a super-2 number, since 2×321891504217² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (321891504227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160945752108 + 160945752109.

It is an arithmetic number, because the mean of its divisors is an integer number (160945752109).

Almost surely, 2^321891504217 is an apocalyptic number.

It is an amenable number.

321891504217 is a deficient number, since it is larger than the sum of its proper divisors (1).

321891504217 is an equidigital number, since it uses as much as digits as its factorization.

321891504217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 43.

The spelling of 321891504217 in words is "three hundred twenty-one billion, eight hundred ninety-one million, five hundred four thousand, two hundred seventeen".