20181020 has 24 divisors (see below), whose sum is σ = 43415568. Its totient is φ = 7875200.

The previous prime is 20181019. The next prime is 20181043. The reversal of 20181020 is 2018102.

It is a junction number, because it is equal to n+sod(n) for n = 20180986 and 20181004.

It is a congruent number.

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, 11486 + ... + 13125.

It is an arithmetic number, because the mean of its divisors is an integer number (1808982).

Almost surely, 2^20181020 is an apocalyptic number.

20181020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20181020 is an abundant number, since it is smaller than the sum of its proper divisors (23234548).

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

20181020 is a wasteful number, since it uses less digits than its factorization.

20181020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24661 (or 24659 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 20181020 is about 4492.3290173361. The cubic root of 20181020 is about 272.2582430623.

Adding to 20181020 its reverse (2018102), we get a palindrome (22199122).

The spelling of 20181020 in words is "twenty million, one hundred eighty-one thousand, twenty".