20138208 has 48 divisors (see below), whose sum is σ = 53479440. Its totient is φ = 6634496.

The previous prime is 20138197. The next prime is 20138219. The reversal of 20138208 is 80283102.

It is an interprime number because it is at equal distance from previous prime (20138197) and next prime (20138219).

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 7366 + ... + 9722.

It is an arithmetic number, because the mean of its divisors is an integer number (1114155).

Almost surely, 2^20138208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20138208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26739720).

20138208 is an abundant number, since it is smaller than the sum of its proper divisors (33341232).

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

20138208 is a wasteful number, since it uses less digits than its factorization.

20138208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2459 (or 2451 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 20138208 is about 4487.5614759020. The cubic root of 20138208 is about 272.0655839546.

The spelling of 20138208 in words is "twenty million, one hundred thirty-eight thousand, two hundred eight".