20531136 has 56 divisors (see below), whose sum is σ = 55243984. Its totient is φ = 6727680.

The previous prime is 20531107. The next prime is 20531171. The reversal of 20531136 is 63113502.

It is a congruent number.

It is an unprimeable number.

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, 10836 + ... + 12588.

Almost surely, 2^20531136 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 20531136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27621992).

20531136 is an abundant number, since it is smaller than the sum of its proper divisors (34712848).

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

20531136 is a wasteful number, since it uses less digits than its factorization.

20531136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1829 (or 1819 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 20531136 is about 4531.1296604710. The cubic root of 20531136 is about 273.8236740050.

Adding to 20531136 its reverse (63113502), we get a palindrome (83644638).

The spelling of 20531136 in words is "twenty million, five hundred thirty-one thousand, one hundred thirty-six".