20023540 has 12 divisors (see below), whose sum is σ = 42049476. Its totient is φ = 8009408.

The previous prime is 20023537. The next prime is 20023561. The reversal of 20023540 is 4532002.

It can be written as a sum of positive squares in 2 ways, for example, as 6170256 + 13853284 = 2484^2 + 3722^2 .

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 3 ways as a sum of consecutive naturals, for example, 500569 + ... + 500608.

It is an arithmetic number, because the mean of its divisors is an integer number (3504123).

Almost surely, 2^20023540 is an apocalyptic number.

20023540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20023540 is an abundant number, since it is smaller than the sum of its proper divisors (22025936).

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

20023540 is a wasteful number, since it uses less digits than its factorization.

20023540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1001186 (or 1001184 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 16.

The square root of 20023540 is about 4474.7670330421. The cubic root of 20023540 is about 271.5482155562.

Adding to 20023540 its reverse (4532002), we get a palindrome (24555542).

The spelling of 20023540 in words is "twenty million, twenty-three thousand, five hundred forty".