20985018 has 16 divisors (see below), whose sum is σ = 42545856. Its totient is φ = 6899040.

The previous prime is 20985017. The next prime is 20985049. The reversal of 20985018 is 81058902.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20985018.

It is not an unprimeable number, because it can be changed into a prime (20985017) 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, 23518 + ... + 24393.

It is an arithmetic number, because the mean of its divisors is an integer number (2659116).

Almost surely, 2^20985018 is an apocalyptic number.

20985018 is an abundant number, since it is smaller than the sum of its proper divisors (21560838).

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

20985018 is a wasteful number, since it uses less digits than its factorization.

20985018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47989.

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 20985018 is about 4580.9407330809. The cubic root of 20985018 is about 275.8267921848.

The spelling of 20985018 in words is "twenty million, nine hundred eighty-five thousand, eighteen".