21002120121022 has 4 divisors (see below), whose sum is σ = 31503180181536. Its totient is φ = 10501060060510.

The previous prime is 21002120121013. The next prime is 21002120121049. The reversal of 21002120121022 is 22012102120012.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21002120120987 and 21002120121005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250530030254 + ... + 5250530030257.

It is an arithmetic number, because the mean of its divisors is an integer number (7875795045384).

Almost surely, 2^{21002120121022} is an apocalyptic number.

21002120121022 is a deficient number, since it is larger than the sum of its proper divisors (10501060060514).

21002120121022 is a wasteful number, since it uses less digits than its factorization.

21002120121022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10501060060513.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21002120121022 its reverse (22012102120012), we get a palindrome (43014222241034).

The spelling of 21002120121022 in words is "twenty-one trillion, two billion, one hundred twenty million, one hundred twenty-one thousand, twenty-two".