20511232 has 80 divisors (see below), whose sum is σ = 48121920. Its totient is φ = 8552448.

The previous prime is 20511221. The next prime is 20511251. The reversal of 20511232 is 23211502.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 211408 + ... + 211504.

It is an arithmetic number, because the mean of its divisors is an integer number (601524).

Almost surely, 2^20511232 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 20511232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24060960).

20511232 is an abundant number, since it is smaller than the sum of its proper divisors (27610688).

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

20511232 is an frugal number, since it uses more digits than its factorization.

20511232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 20511232 is about 4528.9327661161. The cubic root of 20511232 is about 273.7351588738.

Adding to 20511232 its reverse (23211502), we get a palindrome (43722734).

The spelling of 20511232 in words is "twenty million, five hundred eleven thousand, two hundred thirty-two".