1204020421 has 4 divisors (see below), whose sum is σ = 1204097344. Its totient is φ = 1203943500.

The previous prime is 1204020413. The next prime is 1204020437. The reversal of 1204020421 is 1240204021.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1204020421 - 2³ = 1204020413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1204020395 and 1204020404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1204020821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5655 + ... + 49396.

It is an arithmetic number, because the mean of its divisors is an integer number (301024336).

Almost surely, 2^1204020421 is an apocalyptic number.

It is an amenable number.

1204020421 is a deficient number, since it is larger than the sum of its proper divisors (76923).

1204020421 is an equidigital number, since it uses as much as digits as its factorization.

1204020421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76922.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 1204020421 is about 34698.9974062652. The cubic root of 1204020421 is about 1063.8440059645.

Adding to 1204020421 its reverse (1240204021), we get a palindrome (2444224442).

The spelling of 1204020421 in words is "one billion, two hundred four million, twenty thousand, four hundred twenty-one".