21525453 has 32 divisors (see below), whose sum is σ = 33926400. Its totient is φ = 13462848.

The previous prime is 21525419. The next prime is 21525463. The reversal of 21525453 is 35452512.

It is a happy number.

It is not a de Polignac number, because 21525453 - 2⁸ = 21525197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28600 + ... + 29342.

It is an arithmetic number, because the mean of its divisors is an integer number (1060200).

Almost surely, 2^21525453 is an apocalyptic number.

It is an amenable number.

21525453 is a deficient number, since it is larger than the sum of its proper divisors (12400947).

21525453 is a wasteful number, since it uses less digits than its factorization.

21525453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 818 (or 812 counting only the distinct ones).

The product of its digits is 6000, while the sum is 27.

The square root of 21525453 is about 4639.5531034788. The cubic root of 21525453 is about 278.1745750622.

Adding to 21525453 its reverse (35452512), we get a palindrome (56977965).

The spelling of 21525453 in words is "twenty-one million, five hundred twenty-five thousand, four hundred fifty-three".