20124004021 has 4 divisors (see below), whose sum is σ = 21953458944. Its totient is φ = 18294549100.

The previous prime is 20124004009. The next prime is 20124004049. The reversal of 20124004021 is 12040042102.

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 20124004021 - 2⁹ = 20124003509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20124003986 and 20124004004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20124004081) 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, 914727445 + ... + 914727466.

It is an arithmetic number, because the mean of its divisors is an integer number (5488364736).

Almost surely, 2^20124004021 is an apocalyptic number.

It is an amenable number.

20124004021 is a deficient number, since it is larger than the sum of its proper divisors (1829454923).

20124004021 is a wasteful number, since it uses less digits than its factorization.

20124004021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1829454922.

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

Adding to 20124004021 its reverse (12040042102), we get a palindrome (32164046123).

The spelling of 20124004021 in words is "twenty billion, one hundred twenty-four million, four thousand, twenty-one".