21525732 has 36 divisors (see below), whose sum is σ = 54791100. Its totient is φ = 7125312.

The previous prime is 21525719. The next prime is 21525733. The reversal of 21525732 is 23752512.

It can be written as a sum of positive squares in 2 ways, for example, as 10074276 + 11451456 = 3174^2 + 3384^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21525696 and 21525705.

It is not an unprimeable number, because it can be changed into a prime (21525733) 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 11 ways as a sum of consecutive naturals, for example, 3358 + ... + 7370.

It is an arithmetic number, because the mean of its divisors is an integer number (1521975).

Almost surely, 2^21525732 is an apocalyptic number.

It is an amenable number.

21525732 is an abundant number, since it is smaller than the sum of its proper divisors (33265368).

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

21525732 is a wasteful number, since it uses less digits than its factorization.

21525732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4172 (or 4167 counting only the distinct ones).

The product of its digits is 4200, while the sum is 27.

The square root of 21525732 is about 4639.5831709325. The cubic root of 21525732 is about 278.1757769009.

The spelling of 21525732 in words is "twenty-one million, five hundred twenty-five thousand, seven hundred thirty-two".