981533221 has 2 divisors, whose sum is σ = 981533222. Its totient is φ = 981533220.

The previous prime is 981533197. The next prime is 981533227. The reversal of 981533221 is 122335189.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 862068321 + 119464900 = 29361^2 + 10930^2 .

It is an emirp because it is prime and its reverse (122335189) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 981533221 - 2⁹ = 981532709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (981533227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 490766610 + 490766611.

It is an arithmetic number, because the mean of its divisors is an integer number (490766611).

Almost surely, 2^981533221 is an apocalyptic number.

It is an amenable number.

981533221 is a deficient number, since it is larger than the sum of its proper divisors (1).

981533221 is an equidigital number, since it uses as much as digits as its factorization.

981533221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 34.

The square root of 981533221 is about 31329.4305885058. The cubic root of 981533221 is about 993.8061220839.

The spelling of 981533221 in words is "nine hundred eighty-one million, five hundred thirty-three thousand, two hundred twenty-one".