21006105102 has 48 divisors (see below), whose sum is σ = 45686946240. Its totient is φ = 6975360000.

The previous prime is 21006105059. The next prime is 21006105143. The reversal of 21006105102 is 20150160012.

21006105102 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 610 + 51 + 0 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7498102 + ... + 7500902.

It is an arithmetic number, because the mean of its divisors is an integer number (951811380).

Almost surely, 2^21006105102 is an apocalyptic number.

21006105102 is an abundant number, since it is smaller than the sum of its proper divisors (24680841138).

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

21006105102 is a wasteful number, since it uses less digits than its factorization.

21006105102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4249 (or 4246 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

Adding to 21006105102 its reverse (20150160012), we get a palindrome (41156265114).

The spelling of 21006105102 in words is "twenty-one billion, six million, one hundred five thousand, one hundred two".