21042102102 has 64 divisors (see below), whose sum is σ = 51321285120. Its totient is φ = 5617569024.

The previous prime is 21042102089. The next prime is 21042102127. The reversal of 21042102102 is 20120124012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 122353 + ... + 238860.

It is an arithmetic number, because the mean of its divisors is an integer number (801895080).

Almost surely, 2^21042102102 is an apocalyptic number.

21042102102 is an abundant number, since it is smaller than the sum of its proper divisors (30279183018).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21042102102 is a wasteful number, since it uses less digits than its factorization.

21042102102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361317.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21042102102 its reverse (20120124012), we get a palindrome (41162226114).

The spelling of 21042102102 in words is "twenty-one billion, forty-two million, one hundred two thousand, one hundred two".