189015221 has 2 divisors, whose sum is σ = 189015222. Its totient is φ = 189015220.

The previous prime is 189015217. The next prime is 189015251. The reversal of 189015221 is 122510981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 186022321 + 2992900 = 13639^2 + 1730^2 .

It is a cyclic number.

It is not a de Polignac number, because 189015221 - 2² = 189015217 is a prime.

It is a Chen prime.

It is equal to p_10503749 and since 189015221 and 10503749 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189015251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94507610 + 94507611.

It is an arithmetic number, because the mean of its divisors is an integer number (94507611).

Almost surely, 2^189015221 is an apocalyptic number.

It is an amenable number.

189015221 is a deficient number, since it is larger than the sum of its proper divisors (1).

189015221 is an equidigital number, since it uses as much as digits as its factorization.

189015221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 29.

The square root of 189015221 is about 13748.2806561402. The cubic root of 189015221 is about 573.8947600931.

The spelling of 189015221 in words is "one hundred eighty-nine million, fifteen thousand, two hundred twenty-one".