21211222121002 has 4 divisors (see below), whose sum is σ = 31816833181506. Its totient is φ = 10605611060500.

The previous prime is 21211222120987. The next prime is 21211222121003. The reversal of 21211222121002 is 20012122211212.

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

It can be written as a sum of positive squares in only one way, i.e., 19364039410681 + 1847182710321 = 4400459^2 + 1359111^2 .

It is not an unprimeable number, because it can be changed into a prime (21211222121003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5302805530249 + ... + 5302805530252.

Almost surely, 2^{21211222121002} is an apocalyptic number.

21211222121002 is a deficient number, since it is larger than the sum of its proper divisors (10605611060504).

21211222121002 is a wasteful number, since it uses less digits than its factorization.

21211222121002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10605611060503.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21211222121002 its reverse (20012122211212), we get a palindrome (41223344332214).

The spelling of 21211222121002 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-two million, one hundred twenty-one thousand, two".