20021002123 has 4 divisors (see below), whose sum is σ = 20055110040. Its totient is φ = 19986894208.

The previous prime is 20021002117. The next prime is 20021002159. The reversal of 20021002123 is 32120012002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20021002123 - 2⁵ = 20021002091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021002723) 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, 17053078 + ... + 17054251.

It is an arithmetic number, because the mean of its divisors is an integer number (5013777510).

Almost surely, 2^20021002123 is an apocalyptic number.

20021002123 is a deficient number, since it is larger than the sum of its proper divisors (34107917).

20021002123 is an equidigital number, since it uses as much as digits as its factorization.

20021002123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34107916.

The product of its (nonzero) digits is 48, while the sum is 13.

Adding to 20021002123 its reverse (32120012002), we get a palindrome (52141014125).

The spelling of 20021002123 in words is "twenty billion, twenty-one million, two thousand, one hundred twenty-three".