21525141 has 16 divisors (see below), whose sum is σ = 31753728. Its totient is φ = 12860400.

The previous prime is 21525139. The next prime is 21525151. The reversal of 21525141 is 14152512.

It is not a de Polignac number, because 21525141 - 2¹ = 21525139 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525121) 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 15 ways as a sum of consecutive naturals, for example, 2251 + ... + 6936.

It is an arithmetic number, because the mean of its divisors is an integer number (1984608).

Almost surely, 2^21525141 is an apocalyptic number.

It is an amenable number.

21525141 is a deficient number, since it is larger than the sum of its proper divisors (10228587).

21525141 is a wasteful number, since it uses less digits than its factorization.

21525141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9272.

The product of its digits is 400, while the sum is 21.

The square root of 21525141 is about 4639.5194794289. The cubic root of 21525141 is about 278.1732310582.

Adding to 21525141 its reverse (14152512), we get a palindrome (35677653).

The spelling of 21525141 in words is "twenty-one million, five hundred twenty-five thousand, one hundred forty-one".