20021023121 has 32 divisors (see below), whose sum is σ = 23808270720. Its totient is φ = 16776175680.

The previous prime is 20021023093. The next prime is 20021023129. The reversal of 20021023121 is 12132012002.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-20021023121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20021023096 and 20021023105.

It is not an unprimeable number, because it can be changed into a prime (20021023129) 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, 924995 + ... + 946391.

It is an arithmetic number, because the mean of its divisors is an integer number (744008460).

Almost surely, 2^20021023121 is an apocalyptic number.

It is an amenable number.

20021023121 is a deficient number, since it is larger than the sum of its proper divisors (3787247599).

20021023121 is a wasteful number, since it uses less digits than its factorization.

20021023121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21486 (or 21464 counting only the distinct ones).

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

Adding to 20021023121 its reverse (12132012002), we get a palindrome (32153035123).

The spelling of 20021023121 in words is "twenty billion, twenty-one million, twenty-three thousand, one hundred twenty-one".