7312013221 has 2 divisors, whose sum is σ = 7312013222. Its totient is φ = 7312013220.

The previous prime is 7312013213. The next prime is 7312013227. The reversal of 7312013221 is 1223102137.

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., 3683276100 + 3628737121 = 60690^2 + 60239^2 .

It is an emirp because it is prime and its reverse (1223102137) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7312013221 - 2³ = 7312013213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7312013192 and 7312013201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7312013227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3656006610 + 3656006611.

It is an arithmetic number, because the mean of its divisors is an integer number (3656006611).

Almost surely, 2^7312013221 is an apocalyptic number.

It is an amenable number.

7312013221 is a deficient number, since it is larger than the sum of its proper divisors (1).

7312013221 is an equidigital number, since it uses as much as digits as its factorization.

7312013221 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.

The square root of 7312013221 is about 85510.3106122297. The cubic root of 7312013221 is about 1940.9409490227.

Adding to 7312013221 its reverse (1223102137), we get a palindrome (8535115358).

The spelling of 7312013221 in words is "seven billion, three hundred twelve million, thirteen thousand, two hundred twenty-one".