7220138161 has 2 divisors, whose sum is σ = 7220138162. Its totient is φ = 7220138160.

The previous prime is 7220138143. The next prime is 7220138197. The reversal of 7220138161 is 1618310227.

7220138161 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7118128161 + 102010000 = 84369^2 + 10100^2 .

It is an emirp because it is prime and its reverse (1618310227) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7220138161 - 2¹⁷ = 7220007089 is a prime.

It is not a weakly prime, because it can be changed into another prime (7220138131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3610069080 + 3610069081.

It is an arithmetic number, because the mean of its divisors is an integer number (3610069081).

Almost surely, 2^7220138161 is an apocalyptic number.

It is an amenable number.

7220138161 is a deficient number, since it is larger than the sum of its proper divisors (1).

7220138161 is an equidigital number, since it uses as much as digits as its factorization.

7220138161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 7220138161 is about 84971.3961342286. The cubic root of 7220138161 is about 1932.7773878664. Note that the first 3 decimals are identical.

Adding to 7220138161 its reverse (1618310227), we get a palindrome (8838448388).

The spelling of 7220138161 in words is "seven billion, two hundred twenty million, one hundred thirty-eight thousand, one hundred sixty-one".