20138306 has 4 divisors (see below), whose sum is σ = 30207462. Its totient is φ = 10069152.

The previous prime is 20138303. The next prime is 20138311. The reversal of 20138306 is 60383102.

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., 10621081 + 9517225 = 3259^2 + 3085^2 .

It is not an unprimeable number, because it can be changed into a prime (20138303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5034575 + ... + 5034578.

Almost surely, 2^20138306 is an apocalyptic number.

20138306 is a deficient number, since it is larger than the sum of its proper divisors (10069156).

20138306 is a wasteful number, since it uses less digits than its factorization.

20138306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10069155.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 20138306 is about 4487.5723949592. The cubic root of 20138306 is about 272.0660252780.

The spelling of 20138306 in words is "twenty million, one hundred thirty-eight thousand, three hundred six".