21214500 has 48 divisors (see below), whose sum is σ = 61780992. Its totient is φ = 5656800.

The previous prime is 21214493. The next prime is 21214517. The reversal of 21214500 is 541212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21214500.

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 in 15 ways as a sum of consecutive naturals, for example, 5572 + ... + 8571.

It is an arithmetic number, because the mean of its divisors is an integer number (1287104).

Almost surely, 2^21214500 is an apocalyptic number.

21214500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21214500 is an abundant number, since it is smaller than the sum of its proper divisors (40566492).

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

21214500 is a wasteful number, since it uses less digits than its factorization.

21214500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14165 (or 14153 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 21214500 is about 4605.9201035189. The cubic root of 21214500 is about 276.8285854014.

Adding to 21214500 its reverse (541212), we get a palindrome (21755712).

The spelling of 21214500 in words is "twenty-one million, two hundred fourteen thousand, five hundred".