20718845 has 16 divisors (see below), whose sum is σ = 28494720.
Its totient is φ = 14167104.
The previous prime is 20718839. The next prime is 20718851. The reversal of 20718845 is 54881702.
It is an interprime number because it is at equal distance from previous prime (20718839) and next prime (20718851).
It is not a de Polignac number, because 20718845 - 26 = 20718781 is a prime.
It is a Harshad number since it is a multiple of its sum of digits (35).
It is a congruent number.
It is an unprimeable number.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17234 + ... + 18396.
It is an arithmetic number, because the mean of its divisors is an integer number (1780920).
Almost surely, 220718845 is an apocalyptic number.
It is an amenable number.
20718845 is a deficient number, since it is larger than the sum of its proper divisors (7775875).
20718845 is a wasteful number, since it uses less digits than its factorization.
20718845 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1684.
The product of its (nonzero) digits is 17920, while the sum is 35.
The square root of 20718845 is about 4551.7957994620.
The cubic root of 20718845 is about 274.6556350695.
The spelling of 20718845 in words is "twenty million, seven hundred eighteen thousand, eight hundred forty-five".