987221189 has 2 divisors, whose sum is σ = 987221190. Its totient is φ = 987221188.

The previous prime is 987221159. The next prime is 987221201. The reversal of 987221189 is 981122789.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 674285089 + 312936100 = 25967^2 + 17690^2 .

It is a cyclic number.

It is not a de Polignac number, because 987221189 - 2⁸ = 987220933 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 (987221119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 493610594 + 493610595.

It is an arithmetic number, because the mean of its divisors is an integer number (493610595).

Almost surely, 2^987221189 is an apocalyptic number.

It is an amenable number.

987221189 is a deficient number, since it is larger than the sum of its proper divisors (1).

987221189 is an equidigital number, since it uses as much as digits as its factorization.

987221189 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 47.

The square root of 987221189 is about 31420.0762093283. The cubic root of 987221189 is about 995.7221221902.

The spelling of 987221189 in words is "nine hundred eighty-seven million, two hundred twenty-one thousand, one hundred eighty-nine".