21725532 has 18 divisors (see below), whose sum is σ = 54917408. Its totient is φ = 7241832.

The previous prime is 21725519. The next prime is 21725533. The reversal of 21725532 is 23552712.

It is a tau number, because it is divible by the number of its divisors (18).

It is a junction number, because it is equal to n+sod(n) for n = 21725496 and 21725505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21725533) 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 5 ways as a sum of consecutive naturals, for example, 301708 + ... + 301779.

Almost surely, 2^21725532 is an apocalyptic number.

It is an amenable number.

21725532 is an abundant number, since it is smaller than the sum of its proper divisors (33191876).

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

21725532 is a wasteful number, since it uses less digits than its factorization.

21725532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603497 (or 603492 counting only the distinct ones).

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

The square root of 21725532 is about 4661.0655434139. The cubic root of 21725532 is about 279.0337955747.

The spelling of 21725532 in words is "twenty-one million, seven hundred twenty-five thousand, five hundred thirty-two".