156120221 has 2 divisors, whose sum is σ = 156120222. Its totient is φ = 156120220.

The previous prime is 156120193. The next prime is 156120227. The reversal of 156120221 is 122021651.

156120221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149940025 + 6180196 = 12245^2 + 2486^2 .

It is an emirp because it is prime and its reverse (122021651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 156120221 - 2¹⁴ = 156103837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 156120193 and 156120202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (156120227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78060110 + 78060111.

It is an arithmetic number, because the mean of its divisors is an integer number (78060111).

Almost surely, 2^156120221 is an apocalyptic number.

It is an amenable number.

156120221 is a deficient number, since it is larger than the sum of its proper divisors (1).

156120221 is an equidigital number, since it uses as much as digits as its factorization.

156120221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 156120221 is about 12494.8077616264. The cubic root of 156120221 is about 538.4595110007.

Adding to 156120221 its reverse (122021651), we get a palindrome (278141872).

The spelling of 156120221 in words is "one hundred fifty-six million, one hundred twenty thousand, two hundred twenty-one".