1021204421 has 4 divisors (see below), whose sum is σ = 1022061612. Its totient is φ = 1020347232.

The previous prime is 1021204411. The next prime is 1021204427. The reversal of 1021204421 is 1244021201.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 272580100 + 748624321 = 16510^2 + 27361^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021204421 - 2¹⁰ = 1021203397 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1021204421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021204427) 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, 426806 + ... + 429191.

It is an arithmetic number, because the mean of its divisors is an integer number (255515403).

Almost surely, 2^1021204421 is an apocalyptic number.

It is an amenable number.

1021204421 is a deficient number, since it is larger than the sum of its proper divisors (857191).

1021204421 is an equidigital number, since it uses as much as digits as its factorization.

1021204421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 857190.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 1021204421 is about 31956.2892245016. The cubic root of 1021204421 is about 1007.0187620574.

Adding to 1021204421 its reverse (1244021201), we get a palindrome (2265225622).

The spelling of 1021204421 in words is "one billion, twenty-one million, two hundred four thousand, four hundred twenty-one".