1021938221 has 8 divisors (see below), whose sum is σ = 1119364920. Its totient is φ = 928657408.

The previous prime is 1021938193. The next prime is 1021938227. The reversal of 1021938221 is 1228391201.

It can be written as a sum of positive squares in 4 ways, for example, as 462852196 + 559086025 = 21514^2 + 23645^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1021938221 - 2¹⁰ = 1021937197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021938227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1035956 + ... + 1036941.

It is an arithmetic number, because the mean of its divisors is an integer number (139920615).

Almost surely, 2^1021938221 is an apocalyptic number.

It is an amenable number.

1021938221 is a deficient number, since it is larger than the sum of its proper divisors (97426699).

1021938221 is a wasteful number, since it uses less digits than its factorization.

1021938221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2072943.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 1021938221 is about 31967.7684707582. The cubic root of 1021938221 is about 1007.2599065429.

The spelling of 1021938221 in words is "one billion, twenty-one million, nine hundred thirty-eight thousand, two hundred twenty-one".