921082221 has 12 divisors (see below), whose sum is σ = 1344169372. Its totient is φ = 607723776.

The previous prime is 921082207. The next prime is 921082223. The reversal of 921082221 is 122280129.

It can be written as a sum of positive squares in 2 ways, for example, as 735168996 + 185913225 = 27114^2 + 13635^2 .

It is not a de Polignac number, because 921082221 - 2⁶ = 921082157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (921082223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 526666 + ... + 528411.

Almost surely, 2^921082221 is an apocalyptic number.

It is an amenable number.

921082221 is a deficient number, since it is larger than the sum of its proper divisors (423087151).

921082221 is a wasteful number, since it uses less digits than its factorization.

921082221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1055180 (or 1055177 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 921082221 is about 30349.3364177868. The cubic root of 921082221 is about 972.9700376699.

The spelling of 921082221 in words is "nine hundred twenty-one million, eighty-two thousand, two hundred twenty-one".