1000021021 has 4 divisors (see below), whose sum is σ = 1021298112. Its totient is φ = 978743932.

The previous prime is 1000021019. The next prime is 1000021027. The reversal of 1000021021 is 1201200001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1000021021 - 2¹ = 1000021019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1000020995 and 1000021013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000021027) 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 3 ways as a sum of consecutive naturals, for example, 10638475 + ... + 10638568.

It is an arithmetic number, because the mean of its divisors is an integer number (255324528).

Almost surely, 2^1000021021 is an apocalyptic number.

It is an amenable number.

1000021021 is a deficient number, since it is larger than the sum of its proper divisors (21277091).

1000021021 is an equidigital number, since it uses as much as digits as its factorization.

1000021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21277090.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 1000021021 is about 31623.1089711306. The cubic root of 1000021021 is about 1000.0070069509.

Adding to 1000021021 its reverse (1201200001), we get a palindrome (2201221022).

The spelling of 1000021021 in words is "one billion, twenty-one thousand, twenty-one".