20604538 has 4 divisors (see below), whose sum is σ = 30906810. Its totient is φ = 10302268.

The previous prime is 20604503. The next prime is 20604539. The reversal of 20604538 is 83540602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83540602 = 2 ⋅41770301.

It can be written as a sum of positive squares in only one way, i.e., 19474569 + 1129969 = 4413^2 + 1063^2 .

It is not an unprimeable number, because it can be changed into a prime (20604539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5151133 + ... + 5151136.

Almost surely, 2^20604538 is an apocalyptic number.

20604538 is a deficient number, since it is larger than the sum of its proper divisors (10302272).

20604538 is a wasteful number, since it uses less digits than its factorization.

20604538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10302271.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 20604538 is about 4539.2221800657. Note that the first 3 decimals coincide. The cubic root of 20604538 is about 274.1496066143.

The spelling of 20604538 in words is "twenty million, six hundred four thousand, five hundred thirty-eight".