21470500 has 48 divisors (see below), whose sum is σ = 48956544. Its totient is φ = 8210400.

The previous prime is 21470497. The next prime is 21470509. The reversal of 21470500 is 507412.

It is not an unprimeable number, because it can be changed into a prime (21470509) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10567 + ... + 12433.

It is an arithmetic number, because the mean of its divisors is an integer number (1019928).

Almost surely, 2^21470500 is an apocalyptic number.

21470500 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 21470500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24478272).

21470500 is an abundant number, since it is smaller than the sum of its proper divisors (27486044).

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

21470500 is a wasteful number, since it uses less digits than its factorization.

21470500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1909 (or 1897 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 19.

The square root of 21470500 is about 4633.6270890092. The cubic root of 21470500 is about 277.9376531510.

Adding to 21470500 its reverse (507412), we get a palindrome (21977912).

The spelling of 21470500 in words is "twenty-one million, four hundred seventy thousand, five hundred".