21539152 has 20 divisors (see below), whose sum is σ = 41841940. Its totient is φ = 10741248.

The previous prime is 21539149. The next prime is 21539183. The reversal of 21539152 is 25193512.

It can be written as a sum of positive squares in 2 ways, for example, as 3083536 + 18455616 = 1756^2 + 4296^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21539152.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5374 + ... + 8482.

It is an arithmetic number, because the mean of its divisors is an integer number (2092097).

Almost surely, 2^21539152 is an apocalyptic number.

It is an amenable number.

21539152 is a deficient number, since it is larger than the sum of its proper divisors (20302788).

21539152 is a wasteful number, since it uses less digits than its factorization.

21539152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3550 (or 3544 counting only the distinct ones).

The product of its digits is 2700, while the sum is 28.

The square root of 21539152 is about 4641.0291962021. The cubic root of 21539152 is about 278.2335735170.

The spelling of 21539152 in words is "twenty-one million, five hundred thirty-nine thousand, one hundred fifty-two".