20013122021 has 4 divisors (see below), whose sum is σ = 20028625344. Its totient is φ = 19997618700.

The previous prime is 20013121979. The next prime is 20013122027. The reversal of 20013122021 is 12022131002.

It is a happy number.

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 20013122021 - 2¹⁰ = 20013120997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20013121987 and 20013122005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20013122027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7749725 + ... + 7752306.

It is an arithmetic number, because the mean of its divisors is an integer number (5007156336).

Almost surely, 2^20013122021 is an apocalyptic number.

It is an amenable number.

20013122021 is a deficient number, since it is larger than the sum of its proper divisors (15503323).

20013122021 is a wasteful number, since it uses less digits than its factorization.

20013122021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15503322.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 20013122021 its reverse (12022131002), we get a palindrome (32035253023).

The spelling of 20013122021 in words is "twenty billion, thirteen million, one hundred twenty-two thousand, twenty-one".