20144540 has 24 divisors (see below), whose sum is σ = 45558240. Its totient is φ = 7437888.

The previous prime is 20144521. The next prime is 20144549. The reversal of 20144540 is 4544102.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20144549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38480 + ... + 38999.

It is an arithmetic number, because the mean of its divisors is an integer number (1898260).

Almost surely, 2^20144540 is an apocalyptic number.

20144540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20144540 is an abundant number, since it is smaller than the sum of its proper divisors (25413700).

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

20144540 is a wasteful number, since it uses less digits than its factorization.

20144540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77501 (or 77499 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 20144540 is about 4488.2669261086. The cubic root of 20144540 is about 272.0940959048.

Adding to 20144540 its reverse (4544102), we get a palindrome (24688642).

The spelling of 20144540 in words is "twenty million, one hundred forty-four thousand, five hundred forty".