21100450 has 72 divisors (see below), whose sum is σ = 47621952. Its totient is φ = 6812640.

The previous prime is 21100447. The next prime is 21100463. The reversal of 21100450 is 5400112.

It is a self number, because there is not a number n which added to its sum of digits gives 21100450.

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 35 ways as a sum of consecutive naturals, for example, 126267 + ... + 126433.

It is an arithmetic number, because the mean of its divisors is an integer number (661416).

Almost surely, 2^21100450 is an apocalyptic number.

21100450 is an abundant number, since it is smaller than the sum of its proper divisors (26521502).

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

21100450 is a wasteful number, since it uses less digits than its factorization.

21100450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 21100450 is about 4593.5226134199. The cubic root of 21100450 is about 276.3316132403.

Adding to 21100450 its reverse (5400112), we get a palindrome (26500562).

The spelling of 21100450 in words is "twenty-one million, one hundred thousand, four hundred fifty".