21102000 has 80 divisors (see below), whose sum is σ = 68052192. Its totient is φ = 5625600.

The previous prime is 21101963. The next prime is 21102023. The reversal of 21102000 is 20112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21102000.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4242 + ... + 7758.

Almost surely, 2^21102000 is an apocalyptic number.

21102000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21102000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34026096).

21102000 is an abundant number, since it is smaller than the sum of its proper divisors (46950192).

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

21102000 is a wasteful number, since it uses less digits than its factorization.

21102000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3543 (or 3527 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

The square root of 21102000 is about 4593.6913261559. The cubic root of 21102000 is about 276.3383793442.

Adding to 21102000 its reverse (20112), we get a palindrome (21122112).

The spelling of 21102000 in words is "twenty-one million, one hundred two thousand".