1021020221 has 8 divisors (see below), whose sum is σ = 1164240504. Its totient is φ = 887040000.

The previous prime is 1021020199. The next prime is 1021020227. The reversal of 1021020221 is 1220201201.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 368217721 + 652802500 = 19189^2 + 25550^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1021020221 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 (1021020227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2309780 + ... + 2310221.

It is an arithmetic number, because the mean of its divisors is an integer number (145530063).

Almost surely, 2^1021020221 is an apocalyptic number.

It is an amenable number.

1021020221 is a deficient number, since it is larger than the sum of its proper divisors (143220283).

1021020221 is a wasteful number, since it uses less digits than its factorization.

1021020221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4620031.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1021020221 is about 31953.4070327407. The cubic root of 1021020221 is about 1006.9582113305.

Adding to 1021020221 its reverse (1220201201), we get a palindrome (2241221422).

The spelling of 1021020221 in words is "one billion, twenty-one million, twenty thousand, two hundred twenty-one".