21010020002 has 8 divisors (see below), whose sum is σ = 31524984300. Its totient is φ = 10501691904.

The previous prime is 21010019999. The next prime is 21010020007. The reversal of 21010020002 is 20002001012.

It can be written as a sum of positive squares in 2 ways, for example, as 19594680361 + 1415339641 = 139981^2 + 37621^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21010020007) 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 3 ways as a sum of consecutive naturals, for example, 1651127 + ... + 1663802.

Almost surely, 2^21010020002 is an apocalyptic number.

21010020002 is a deficient number, since it is larger than the sum of its proper divisors (10514964298).

21010020002 is a wasteful number, since it uses less digits than its factorization.

21010020002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3318100.

The product of its (nonzero) digits is 8, while the sum is 8.

Adding to 21010020002 its reverse (20002001012), we get a palindrome (41012021014).

The spelling of 21010020002 in words is "twenty-one billion, ten million, twenty thousand, two".