21001120022002 has 4 divisors (see below), whose sum is σ = 31501680033006. Its totient is φ = 10500560011000.

The previous prime is 21001120021993. The next prime is 21001120022009. The reversal of 21001120022002 is 20022002110012.

It is a happy number.

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., 12087366402721 + 8913753619281 = 3476689^2 + 2985591^2 .

It is not an unprimeable number, because it can be changed into a prime (21001120022009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250280005499 + ... + 5250280005502.

Almost surely, 2^{21001120022002} is an apocalyptic number.

21001120022002 is a deficient number, since it is larger than the sum of its proper divisors (10500560011004).

21001120022002 is a wasteful number, since it uses less digits than its factorization.

21001120022002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10500560011003.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21001120022002 its reverse (20022002110012), we get a palindrome (41023122132014).

The spelling of 21001120022002 in words is "twenty-one trillion, one billion, one hundred twenty million, twenty-two thousand, two".