20532640 has 48 divisors (see below), whose sum is σ = 48845160. Its totient is φ = 8156160.

The previous prime is 20532613. The next prime is 20532641. The reversal of 20532640 is 4623502.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5817744 + 14714896 = 2412^2 + 3836^2 .

It is not an unprimeable number, because it can be changed into a prime (20532641) 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 7 ways as a sum of consecutive naturals, for example, 28606 + ... + 29314.

Almost surely, 2^20532640 is an apocalyptic number.

20532640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20532640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24422580).

20532640 is an abundant number, since it is smaller than the sum of its proper divisors (28312520).

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

20532640 is a wasteful number, since it uses less digits than its factorization.

20532640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905 (or 897 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 22.

The square root of 20532640 is about 4531.2956204600. The cubic root of 20532640 is about 273.8303601223.

The spelling of 20532640 in words is "twenty million, five hundred thirty-two thousand, six hundred forty".