20138040 has 144 divisors (see below), whose sum is σ = 71084520. Its totient is φ = 4942080.

The previous prime is 20138033. The next prime is 20138071. The reversal of 20138040 is 4083102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 60675 + ... + 61005.

Almost surely, 2^20138040 is an apocalyptic number.

20138040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20138040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35542260).

20138040 is an abundant number, since it is smaller than the sum of its proper divisors (50946480).

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

20138040 is a wasteful number, since it uses less digits than its factorization.

20138040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 20138040 is about 4487.5427574565. The cubic root of 20138040 is about 272.0648273970.

The spelling of 20138040 in words is "twenty million, one hundred thirty-eight thousand, forty".