21012002002 has 16 divisors (see below), whose sum is σ = 32373841752. Its totient is φ = 10220791680.

The previous prime is 21012001991. The next prime is 21012002009. The reversal of 21012002002 is 20020021012.

It can be written as a sum of positive squares in 4 ways, for example, as 9584605801 + 11427396201 = 97901^2 + 106899^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21012002002.

It is not an unprimeable number, because it can be changed into a prime (21012002009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 925102 + ... + 947542.

Almost surely, 2^21012002002 is an apocalyptic number.

21012002002 is a deficient number, since it is larger than the sum of its proper divisors (11361839750).

21012002002 is a wasteful number, since it uses less digits than its factorization.

21012002002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35133.

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21012002002 its reverse (20020021012), we get a palindrome (41032023014).

The spelling of 21012002002 in words is "twenty-one billion, twelve million, two thousand, two".