21020012102002 has 4 divisors (see below), whose sum is σ = 31530018153006. Its totient is φ = 10510006051000.

The previous prime is 21020012101889. The next prime is 21020012102059. The reversal of 21020012102002 is 20020121002012.

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., 21017814461361 + 2197640641 = 4584519^2 + 46879^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5255003025499 + ... + 5255003025502.

Almost surely, 2^{21020012102002} is an apocalyptic number.

21020012102002 is a deficient number, since it is larger than the sum of its proper divisors (10510006051004).

21020012102002 is a wasteful number, since it uses less digits than its factorization.

21020012102002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10510006051003.

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

Adding to 21020012102002 its reverse (20020121002012), we get a palindrome (41040133104014).

The spelling of 21020012102002 in words is "twenty-one trillion, twenty billion, twelve million, one hundred two thousand, two".