21025360 has 40 divisors (see below), whose sum is σ = 49449960. Its totient is φ = 8312832.

The previous prime is 21025357. The next prime is 21025363. The reversal of 21025360 is 6352012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21025357) and next prime (21025363).

It can be written as a sum of positive squares in 4 ways, for example, as 2155024 + 18870336 = 1468^2 + 4344^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21025363) 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, 5644 + ... + 8596.

It is an arithmetic number, because the mean of its divisors is an integer number (1236249).

Almost surely, 2^21025360 is an apocalyptic number.

21025360 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 21025360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24724980).

21025360 is an abundant number, since it is smaller than the sum of its proper divisors (28424600).

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

21025360 is a wasteful number, since it uses less digits than its factorization.

21025360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3055 (or 3049 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21025360 is about 4585.3418629367. The cubic root of 21025360 is about 276.0034306092.

Adding to 21025360 its reverse (6352012), we get a palindrome (27377372).

The spelling of 21025360 in words is "twenty-one million, twenty-five thousand, three hundred sixty".