31211230217 has 2 divisors, whose sum is σ = 31211230218. Its totient is φ = 31211230216.

The previous prime is 31211230199. The next prime is 31211230333. The reversal of 31211230217 is 71203211213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19368567241 + 11842662976 = 139171^2 + 108824^2 .

It is a cyclic number.

It is not a de Polignac number, because 31211230217 - 2⁶ = 31211230153 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31211230192 and 31211230201.

It is not a weakly prime, because it can be changed into another prime (31211230717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15605615108 + 15605615109.

It is an arithmetic number, because the mean of its divisors is an integer number (15605615109).

Almost surely, 2^31211230217 is an apocalyptic number.

It is an amenable number.

31211230217 is a deficient number, since it is larger than the sum of its proper divisors (1).

31211230217 is an equidigital number, since it uses as much as digits as its factorization.

31211230217 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 23.

The spelling of 31211230217 in words is "thirty-one billion, two hundred eleven million, two hundred thirty thousand, two hundred seventeen".