21001002122203 has 4 divisors (see below), whose sum is σ = 21140081606608. Its totient is φ = 20861922637800.

The previous prime is 21001002122183. The next prime is 21001002122209. The reversal of 21001002122203 is 30222120010012.

It is a happy number.

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 21001002122203 - 2¹⁷ = 21001001991131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001002122209) 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, 69539741976 + ... + 69539742277.

It is an arithmetic number, because the mean of its divisors is an integer number (5285020401652).

Almost surely, 2^{21001002122203} is an apocalyptic number.

21001002122203 is a deficient number, since it is larger than the sum of its proper divisors (139079484405).

21001002122203 is a wasteful number, since it uses less digits than its factorization.

21001002122203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139079484404.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21001002122203 its reverse (30222120010012), we get a palindrome (51223122132215).

The spelling of 21001002122203 in words is "twenty-one trillion, one billion, two million, one hundred twenty-two thousand, two hundred three".