20815552 has 56 divisors (see below), whose sum is σ = 43891200. Its totient is φ = 9774336.

The previous prime is 20815547. The next prime is 20815559. The reversal of 20815552 is 25551802.

It is a self number, because there is not a number n which added to its sum of digits gives 20815552.

It is not an unprimeable number, because it can be changed into a prime (20815559) 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, 116199 + ... + 116377.

Almost surely, 2^20815552 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20815552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21945600).

20815552 is an abundant number, since it is smaller than the sum of its proper divisors (23075648).

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

20815552 is a wasteful number, since it uses less digits than its factorization.

20815552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293 (or 283 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 28.

The square root of 20815552 is about 4562.4063826012. The cubic root of 20815552 is about 275.0822982335.

The spelling of 20815552 in words is "twenty million, eight hundred fifteen thousand, five hundred fifty-two".