21120102 has 24 divisors (see below), whose sum is σ = 47456136. Its totient is φ = 7039872.

The previous prime is 21120089. The next prime is 21120109. The reversal of 21120102 is 20102112.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21243 + ... + 22214.

It is an arithmetic number, because the mean of its divisors is an integer number (1977339).

Almost surely, 2^21120102 is an apocalyptic number.

21120102 is an abundant number, since it is smaller than the sum of its proper divisors (26336034).

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

21120102 is an equidigital number, since it uses as much as digits as its factorization.

21120102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43474 (or 43462 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 21120102 is about 4595.6612146676. The cubic root of 21120102 is about 276.4173741891.

Adding to 21120102 its reverse (20102112), we get a palindrome (41222214).

The spelling of 21120102 in words is "twenty-one million, one hundred twenty thousand, one hundred two".