21200102002 has 4 divisors (see below), whose sum is σ = 31800153006. Its totient is φ = 10600051000.

The previous prime is 21200101963. The next prime is 21200102003. The reversal of 21200102002 is 20020100212.

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., 16093713321 + 5106388681 = 126861^2 + 71459^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21200102002.

It is not an unprimeable number, because it can be changed into a prime (21200102003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5300025499 + ... + 5300025502.

Almost surely, 2^21200102002 is an apocalyptic number.

21200102002 is a deficient number, since it is larger than the sum of its proper divisors (10600051004).

21200102002 is a wasteful number, since it uses less digits than its factorization.

21200102002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10600051003.

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

Adding to 21200102002 its reverse (20020100212), we get a palindrome (41220202214).

The spelling of 21200102002 in words is "twenty-one billion, two hundred million, one hundred two thousand, two".