21210112102 has 4 divisors (see below), whose sum is σ = 31815168156. Its totient is φ = 10605056050.

The previous prime is 21210112069. The next prime is 21210112109. The reversal of 21210112102 is 20121101212.

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 (21210112109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5302528024 + ... + 5302528027.

It is an arithmetic number, because the mean of its divisors is an integer number (7953792039).

Almost surely, 2^21210112102 is an apocalyptic number.

21210112102 is a deficient number, since it is larger than the sum of its proper divisors (10605056054).

21210112102 is a wasteful number, since it uses less digits than its factorization.

21210112102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10605056053.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21210112102 its reverse (20121101212), we get a palindrome (41331213314).

The spelling of 21210112102 in words is "twenty-one billion, two hundred ten million, one hundred twelve thousand, one hundred two".