20138738 has 4 divisors (see below), whose sum is σ = 30208110. Its totient is φ = 10069368.

The previous prime is 20138707. The next prime is 20138743. The reversal of 20138738 is 83783102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 19509889 + 628849 = 4417^2 + 793^2 .

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5034683 + ... + 5034686.

Almost surely, 2^20138738 is an apocalyptic number.

20138738 is a deficient number, since it is larger than the sum of its proper divisors (10069372).

20138738 is a wasteful number, since it uses less digits than its factorization.

20138738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10069371.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 20138738 is about 4487.6205276293. The cubic root of 20138738 is about 272.0679706862.

The spelling of 20138738 in words is "twenty million, one hundred thirty-eight thousand, seven hundred thirty-eight".