20018478 has 16 divisors (see below), whose sum is σ = 40968576. Its totient is φ = 6517560.

The previous prime is 20018477. The next prime is 20018489. The reversal of 20018478 is 87481002.

It is a super-2 number, since 2×20018478² = 801478922872968, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20018477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38538 + ... + 39053.

It is an arithmetic number, because the mean of its divisors is an integer number (2560536).

Almost surely, 2^20018478 is an apocalyptic number.

20018478 is an abundant number, since it is smaller than the sum of its proper divisors (20950098).

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

20018478 is a wasteful number, since it uses less digits than its factorization.

20018478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77639.

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 20018478 is about 4474.2013812523. The cubic root of 20018478 is about 271.5253309428.

The spelling of 20018478 in words is "twenty million, eighteen thousand, four hundred seventy-eight".