156099221 has 2 divisors, whose sum is σ = 156099222. Its totient is φ = 156099220.

The previous prime is 156099187. The next prime is 156099239. The reversal of 156099221 is 122990651.

156099221 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., 155127025 + 972196 = 12455^2 + 986^2 .

It is a cyclic number.

It is not a de Polignac number, because 156099221 - 2⁶ = 156099157 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (156099271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78049610 + 78049611.

It is an arithmetic number, because the mean of its divisors is an integer number (78049611).

Almost surely, 2^156099221 is an apocalyptic number.

It is an amenable number.

156099221 is a deficient number, since it is larger than the sum of its proper divisors (1).

156099221 is an equidigital number, since it uses as much as digits as its factorization.

156099221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 156099221 is about 12493.9673843019. The cubic root of 156099221 is about 538.4353668792.

The spelling of 156099221 in words is "one hundred fifty-six million, ninety-nine thousand, two hundred twenty-one".