20717540 has 24 divisors (see below), whose sum is σ = 43690752. Its totient is φ = 8252000.

The previous prime is 20717537. The next prime is 20717569. The reversal of 20717540 is 4571702.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2957 + ... + 7083.

It is an arithmetic number, because the mean of its divisors is an integer number (1820448).

Almost surely, 2^20717540 is an apocalyptic number.

20717540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20717540 is an abundant number, since it is smaller than the sum of its proper divisors (22973212).

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

20717540 is a wasteful number, since it uses less digits than its factorization.

20717540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4387 (or 4385 counting only the distinct ones).

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 20717540 is about 4551.6524471888. The cubic root of 20717540 is about 274.6498684493.

The spelling of 20717540 in words is "twenty million, seven hundred seventeen thousand, five hundred forty".