21486500 has 72 divisors (see below), whose sum is σ = 54650232. Its totient is φ = 7358400.

The previous prime is 21486467. The next prime is 21486523. The reversal of 21486500 is 568412.

It can be written as a sum of positive squares in 4 ways, for example, as 12544 + 21473956 = 112^2 + 4634^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21486500.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24062 + ... + 24938.

It is an arithmetic number, because the mean of its divisors is an integer number (759031).

Almost surely, 2^21486500 is an apocalyptic number.

21486500 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 21486500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27325116).

21486500 is an abundant number, since it is smaller than the sum of its proper divisors (33163732).

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

21486500 is a wasteful number, since it uses less digits than its factorization.

21486500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910 (or 891 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 21486500 is about 4635.3532767201. The cubic root of 21486500 is about 278.0066765127.

The spelling of 21486500 in words is "twenty-one million, four hundred eighty-six thousand, five hundred".