21020000102 has 4 divisors (see below), whose sum is σ = 31530000156. Its totient is φ = 10510000050.

The previous prime is 21020000087. The next prime is 21020000119. The reversal of 21020000102 is 20100002012.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21020000102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5255000024 + ... + 5255000027.

It is an arithmetic number, because the mean of its divisors is an integer number (7882500039).

Almost surely, 2^21020000102 is an apocalyptic number.

21020000102 is a deficient number, since it is larger than the sum of its proper divisors (10510000054).

21020000102 is a wasteful number, since it uses less digits than its factorization.

21020000102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10510000053.

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

Adding to 21020000102 its reverse (20100002012), we get a palindrome (41120002114).

The spelling of 21020000102 in words is "twenty-one billion, twenty million, one hundred two", and thus it is an aban number.