21633525 has 18 divisors (see below), whose sum is σ = 38748450. Its totient is φ = 11537760.

The previous prime is 21633499. The next prime is 21633529. The reversal of 21633525 is 52533612.

21633525 is a `hidden beast` number, since 2 + 1 + 633 + 5 + 25 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 7322436 + 14311089 = 2706^2 + 3783^2 .

It is not a de Polignac number, because 21633525 - 2¹³ = 21625333 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21633529) 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 17 ways as a sum of consecutive naturals, for example, 47850 + ... + 48299.

Almost surely, 2^21633525 is an apocalyptic number.

21633525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21633525 is a deficient number, since it is larger than the sum of its proper divisors (17114925).

21633525 is a wasteful number, since it uses less digits than its factorization.

21633525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96165 (or 96157 counting only the distinct ones).

The product of its digits is 5400, while the sum is 27.

The square root of 21633525 is about 4651.1853327942. The cubic root of 21633525 is about 278.6393381916.

The spelling of 21633525 in words is "twenty-one million, six hundred thirty-three thousand, five hundred twenty-five".