20871755 has 4 divisors (see below), whose sum is σ = 25046112. Its totient is φ = 16697400.

The previous prime is 20871743. The next prime is 20871757. The reversal of 20871755 is 55717802.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20871755 - 2⁶ = 20871691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20871757) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2087171 + ... + 2087180.

It is an arithmetic number, because the mean of its divisors is an integer number (6261528).

Almost surely, 2^20871755 is an apocalyptic number.

20871755 is a deficient number, since it is larger than the sum of its proper divisors (4174357).

20871755 is an equidigital number, since it uses as much as digits as its factorization.

20871755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4174356.

The product of its (nonzero) digits is 19600, while the sum is 35.

The square root of 20871755 is about 4568.5615898223. The cubic root of 20871755 is about 275.3296542582.

The spelling of 20871755 in words is "twenty million, eight hundred seventy-one thousand, seven hundred fifty-five".