20785138 has 12 divisors (see below), whose sum is σ = 34270110. Its totient is φ = 9447680.

The previous prime is 20785133. The next prime is 20785147. The reversal of 20785138 is 83158702.

It can be written as a sum of positive squares in only one way, i.e., 12159169 + 8625969 = 3487^2 + 2937^2 .

It is not an unprimeable number, because it can be changed into a prime (20785133) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 42703 + ... + 43186.

Almost surely, 2^20785138 is an apocalyptic number.

20785138 is a deficient number, since it is larger than the sum of its proper divisors (13484972).

20785138 is a wasteful number, since it uses less digits than its factorization.

20785138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85913 (or 85902 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 20785138 is about 4559.0720547059. The cubic root of 20785138 is about 274.9482569315.

The spelling of 20785138 in words is "twenty million, seven hundred eighty-five thousand, one hundred thirty-eight".