21000220102 has 4 divisors (see below), whose sum is σ = 31500330156. Its totient is φ = 10500110050.

The previous prime is 21000220099. The next prime is 21000220103. The reversal of 21000220102 is 20102200012.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000220103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250055024 + ... + 5250055027.

It is an arithmetic number, because the mean of its divisors is an integer number (7875082539).

Almost surely, 2^21000220102 is an apocalyptic number.

21000220102 is a deficient number, since it is larger than the sum of its proper divisors (10500110054).

21000220102 is a wasteful number, since it uses less digits than its factorization.

21000220102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10500110053.

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

Adding to 21000220102 its reverse (20102200012), we get a palindrome (41102420114).

The spelling of 21000220102 in words is "twenty-one billion, two hundred twenty thousand, one hundred two".