1021021021 has 4 divisors (see below), whose sum is σ = 1021092700. Its totient is φ = 1020949344.

The previous prime is 1021021013. The next prime is 1021021033. The reversal of 1021021021 is 1201201201.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 985080996 + 35940025 = 31386^2 + 5995^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021021021 - 2³ = 1021021013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1021020989 and 1021021007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021021121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6426 + ... + 45643.

It is an arithmetic number, because the mean of its divisors is an integer number (255273175).

Almost surely, 2^1021021021 is an apocalyptic number.

It is an amenable number.

1021021021 is a deficient number, since it is larger than the sum of its proper divisors (71679).

1021021021 is an equidigital number, since it uses as much as digits as its factorization.

1021021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71678.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1021021021 is about 31953.4195509651. The cubic root of 1021021021 is about 1006.9584743245.

Adding to 1021021021 its reverse (1201201201), we get a palindrome (2222222222).

The spelling of 1021021021 in words is "one billion, twenty-one million, twenty-one thousand, twenty-one".