20112540 has 72 divisors (see below), whose sum is σ = 65518992. Its totient is φ = 4596480.

The previous prime is 20112523. The next prime is 20112541. The reversal of 20112540 is 4521102.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20112541) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 481 + ... + 6360.

It is an arithmetic number, because the mean of its divisors is an integer number (909986).

Almost surely, 2^20112540 is an apocalyptic number.

20112540 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 20112540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32759496).

20112540 is an abundant number, since it is smaller than the sum of its proper divisors (45406452).

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

20112540 is a wasteful number, since it uses less digits than its factorization.

20112540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6867 (or 6858 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 20112540 is about 4484.7006589069. The cubic root of 20112540 is about 271.9499439318.

Adding to 20112540 its reverse (4521102), we get a palindrome (24633642).

The spelling of 20112540 in words is "twenty million, one hundred twelve thousand, five hundred forty".