20078138 has 8 divisors (see below), whose sum is σ = 30141300. Its totient is φ = 10031040.

The previous prime is 20078137. The next prime is 20078143. The reversal of 20078138 is 83187002.

It can be written as a sum of positive squares in 2 ways, for example, as 19298449 + 779689 = 4393^2 + 883^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20078138.

It is not an unprimeable number, because it can be changed into a prime (20078131) 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 3 ways as a sum of consecutive naturals, for example, 143 + ... + 6338.

Almost surely, 2^20078138 is an apocalyptic number.

20078138 is a deficient number, since it is larger than the sum of its proper divisors (10063162).

20078138 is a wasteful number, since it uses less digits than its factorization.

20078138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8032.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 20078138 is about 4480.8635328472. The cubic root of 20078138 is about 271.7948009011.

The spelling of 20078138 in words is "twenty million, seventy-eight thousand, one hundred thirty-eight".