21025120 has 48 divisors (see below), whose sum is σ = 49947408. Its totient is φ = 8363520.

The previous prime is 21025117. The next prime is 21025127. The reversal of 21025120 is 2152012.

It is a self number, because there is not a number n which added to its sum of digits gives 21025120.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21025127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52762 + ... + 53158.

It is an arithmetic number, because the mean of its divisors is an integer number (1040571).

Almost surely, 2^21025120 is an apocalyptic number.

21025120 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 21025120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24973704).

21025120 is an abundant number, since it is smaller than the sum of its proper divisors (28922288).

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

21025120 is a wasteful number, since it uses less digits than its factorization.

21025120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743 (or 735 counting only the distinct ones).

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

The square root of 21025120 is about 4585.3156925123. The cubic root of 21025120 is about 276.0023804318.

Adding to 21025120 its reverse (2152012), we get a palindrome (23177132).

The spelling of 21025120 in words is "twenty-one million, twenty-five thousand, one hundred twenty".