20204020421 has 8 divisors (see below), whose sum is σ = 21759303384. Its totient is φ = 18648898560.

The previous prime is 20204020399. The next prime is 20204020423. The reversal of 20204020421 is 12402040202.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12780302500 + 7423717921 = 113050^2 + 86161^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20204020421 - 2³⁴ = 3024151237 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20204020421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20204020423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 392501 + ... + 440981.

It is an arithmetic number, because the mean of its divisors is an integer number (2719912923).

Almost surely, 2^20204020421 is an apocalyptic number.

It is an amenable number.

20204020421 is a deficient number, since it is larger than the sum of its proper divisors (1555282963).

20204020421 is a wasteful number, since it uses less digits than its factorization.

20204020421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80551.

The product of its (nonzero) digits is 256, while the sum is 17.

Adding to 20204020421 its reverse (12402040202), we get a palindrome (32606060623).

The spelling of 20204020421 in words is "twenty billion, two hundred four million, twenty thousand, four hundred twenty-one".