20715540 has 24 divisors (see below), whose sum is σ = 58003680. Its totient is φ = 5524128.

The previous prime is 20715517. The next prime is 20715547. The reversal of 20715540 is 4551702.

It is a self number, because there is not a number n which added to its sum of digits gives 20715540.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20715547) 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, 172570 + ... + 172689.

It is an arithmetic number, because the mean of its divisors is an integer number (2416820).

Almost surely, 2^20715540 is an apocalyptic number.

20715540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20715540 is an abundant number, since it is smaller than the sum of its proper divisors (37288140).

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

20715540 is a wasteful number, since it uses less digits than its factorization.

20715540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345271 (or 345269 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 20715540 is about 4551.4327414563. The cubic root of 20715540 is about 274.6410302473.

The spelling of 20715540 in words is "twenty million, seven hundred fifteen thousand, five hundred forty".