21525441 has 8 divisors (see below), whose sum is σ = 32800704. Its totient is φ = 12300240.

The previous prime is 21525419. The next prime is 21525463. The reversal of 21525441 is 14452512.

It is an interprime number because it is at equal distance from previous prime (21525419) and next prime (21525463).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21525441 - 2⁵ = 21525409 is a prime.

It is a super-2 number, since 2×21525441² = 926689220488962, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21525481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 512490 + ... + 512531.

It is an arithmetic number, because the mean of its divisors is an integer number (4100088).

Almost surely, 2^21525441 is an apocalyptic number.

21525441 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21525441 is a deficient number, since it is larger than the sum of its proper divisors (11275263).

21525441 is a wasteful number, since it uses less digits than its factorization.

21525441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1025031.

The product of its digits is 1600, while the sum is 24.

The square root of 21525441 is about 4639.5518102506. The cubic root of 21525441 is about 278.1745233700.

Adding to 21525441 its reverse (14452512), we get a palindrome (35977953).

The spelling of 21525441 in words is "twenty-one million, five hundred twenty-five thousand, four hundred forty-one".