21525376 has 32 divisors (see below), whose sum is σ = 43139880. Its totient is φ = 10698240.

The previous prime is 21525373. The next prime is 21525403. The reversal of 21525376 is 67352512.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525373) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26610 + ... + 27406.

Almost surely, 2^21525376 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21525376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21569940).

21525376 is an abundant number, since it is smaller than the sum of its proper divisors (21614504).

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

21525376 is an equidigital number, since it uses as much as digits as its factorization.

With its predecessor (21525375) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (1010).

21525376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1022 (or 1010 counting only the distinct ones).

The product of its digits is 12600, while the sum is 31.

The square root of 21525376 is about 4639.5448052584. The cubic root of 21525376 is about 278.1742433701.

Adding to 21525376 its reverse (67352512), we get a palindrome (88877888).

The spelling of 21525376 in words is "twenty-one million, five hundred twenty-five thousand, three hundred seventy-six".