20604002021 has 4 divisors (see below), whose sum is σ = 21688423200. Its totient is φ = 19519580844.

The previous prime is 20604002011. The next prime is 20604002033. The reversal of 20604002021 is 12020040602.

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 20604002021 - 2²² = 20599807717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20604002011) 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, 542210561 + ... + 542210598.

It is an arithmetic number, because the mean of its divisors is an integer number (5422105800).

Almost surely, 2^20604002021 is an apocalyptic number.

It is an amenable number.

20604002021 is a deficient number, since it is larger than the sum of its proper divisors (1084421179).

20604002021 is a wasteful number, since it uses less digits than its factorization.

20604002021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1084421178.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 20604002021 its reverse (12020040602), we get a palindrome (32624042623).

The spelling of 20604002021 in words is "twenty billion, six hundred four million, two thousand, twenty-one".