20136540 has 24 divisors (see below), whose sum is σ = 56382480. Its totient is φ = 5369728.

The previous prime is 20136511. The next prime is 20136541. The reversal of 20136540 is 4563102.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20136541) 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, 167745 + ... + 167864.

It is an arithmetic number, because the mean of its divisors is an integer number (2349270).

Almost surely, 2^20136540 is an apocalyptic number.

20136540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20136540 is an abundant number, since it is smaller than the sum of its proper divisors (36245940).

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

20136540 is a wasteful number, since it uses less digits than its factorization.

20136540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335621 (or 335619 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 20136540 is about 4487.3756250174. The cubic root of 20136540 is about 272.0580722316.

Adding to 20136540 its reverse (4563102), we get a palindrome (24699642).

The spelling of 20136540 in words is "twenty million, one hundred thirty-six thousand, five hundred forty".