21615852 has 24 divisors (see below), whose sum is σ = 50706432. Its totient is φ = 7166800.

The previous prime is 21615851. The next prime is 21615871. The reversal of 21615852 is 25851612.

It is not an unprimeable number, because it can be changed into a prime (21615851) 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 7 ways as a sum of consecutive naturals, for example, 2424 + ... + 7007.

It is an arithmetic number, because the mean of its divisors is an integer number (2112768).

Almost surely, 2^21615852 is an apocalyptic number.

It is an amenable number.

21615852 is an abundant number, since it is smaller than the sum of its proper divisors (29090580).

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

21615852 is a wasteful number, since it uses less digits than its factorization.

21615852 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9629 (or 9627 counting only the distinct ones).

The product of its digits is 4800, while the sum is 30.

The square root of 21615852 is about 4649.2851063362. The cubic root of 21615852 is about 278.5634415668.

The spelling of 21615852 in words is "twenty-one million, six hundred fifteen thousand, eight hundred fifty-two".