21245000 has 80 divisors (see below), whose sum is σ = 56981760. Its totient is φ = 7272000.

The previous prime is 21244999. The next prime is 21245027. The reversal of 21245000 is 54212.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 34697 + ... + 35303.

It is an arithmetic number, because the mean of its divisors is an integer number (712272).

Almost surely, 2^21245000 is an apocalyptic number.

21245000 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 21245000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28490880).

21245000 is an abundant number, since it is smaller than the sum of its proper divisors (35736760).

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

21245000 is an equidigital number, since it uses as much as digits as its factorization.

21245000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640 (or 621 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 21245000 is about 4609.2298705966. The cubic root of 21245000 is about 276.9611869836.

Adding to 21245000 its reverse (54212), we get a palindrome (21299212).

The spelling of 21245000 in words is "twenty-one million, two hundred forty-five thousand".