21008102 has 4 divisors (see below), whose sum is σ = 31512156. Its totient is φ = 10504050.

The previous prime is 21008083. The next prime is 21008149. The reversal of 21008102 is 20180012.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5252024 + ... + 5252027.

It is an arithmetic number, because the mean of its divisors is an integer number (7878039).

Almost surely, 2^21008102 is an apocalyptic number.

21008102 is a deficient number, since it is larger than the sum of its proper divisors (10504054).

21008102 is a wasteful number, since it uses less digits than its factorization.

21008102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10504053.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 21008102 is about 4583.4596103817. The cubic root of 21008102 is about 275.9278937169.

Adding to 21008102 its reverse (20180012), we get a palindrome (41188114).

The spelling of 21008102 in words is "twenty-one million, eight thousand, one hundred two".