20423211021 has 32 divisors (see below), whose sum is σ = 30994358400. Its totient is φ = 13286862720.

The previous prime is 20423211019. The next prime is 20423211047. The reversal of 20423211021 is 12011232402.

It is a happy number.

It is not a de Polignac number, because 20423211021 - 2¹ = 20423211019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20423210985 and 20423211003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20423211121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 171451 + ... + 265031.

It is an arithmetic number, because the mean of its divisors is an integer number (968573700).

Almost surely, 2^20423211021 is an apocalyptic number.

It is an amenable number.

20423211021 is a deficient number, since it is larger than the sum of its proper divisors (10571147379).

20423211021 is a wasteful number, since it uses less digits than its factorization.

20423211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93786 (or 93780 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 20423211021 its reverse (12011232402), we get a palindrome (32434443423).

The spelling of 20423211021 in words is "twenty billion, four hundred twenty-three million, two hundred eleven thousand, twenty-one".