20021100121 has 4 divisors (see below), whose sum is σ = 21841200144. Its totient is φ = 18201000100.

The previous prime is 20021100119. The next prime is 20021100137. The reversal of 20021100121 is 12100112002.

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 20021100121 - 2¹ = 20021100119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20021100098 and 20021100107.

It is not an unprimeable number, because it can be changed into a prime (20021100161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 910049995 + ... + 910050016.

It is an arithmetic number, because the mean of its divisors is an integer number (5460300036).

Almost surely, 2^20021100121 is an apocalyptic number.

It is an amenable number.

20021100121 is a deficient number, since it is larger than the sum of its proper divisors (1820100023).

20021100121 is a wasteful number, since it uses less digits than its factorization.

20021100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1820100022.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20021100121 its reverse (12100112002), we get a palindrome (32121212123).

The spelling of 20021100121 in words is "twenty billion, twenty-one million, one hundred thousand, one hundred twenty-one".