21020012102 has 8 divisors (see below), whose sum is σ = 32299043112. Its totient is φ = 10253664400.

The previous prime is 21020012099. The next prime is 21020012129. The reversal of 21020012102 is 20121002012.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128170724 + ... + 128170887.

It is an arithmetic number, because the mean of its divisors is an integer number (4037380389).

Almost surely, 2^21020012102 is an apocalyptic number.

21020012102 is a deficient number, since it is larger than the sum of its proper divisors (11279031010).

21020012102 is a wasteful number, since it uses less digits than its factorization.

21020012102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256341654.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21020012102 its reverse (20121002012), we get a palindrome (41141014114).

The spelling of 21020012102 in words is "twenty-one billion, twenty million, twelve thousand, one hundred two".