20867138 has 4 divisors (see below), whose sum is σ = 31300710. Its totient is φ = 10433568.

The previous prime is 20867131. The next prime is 20867173. The reversal of 20867138 is 83176802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83176802 = 2 ⋅41588401.

It can be written as a sum of positive squares in only one way, i.e., 12439729 + 8427409 = 3527^2 + 2903^2 .

It is a super-2 number, since 2×20867138² = 870874896622088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20867098 and 20867107.

It is not an unprimeable number, because it can be changed into a prime (20867131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5216783 + ... + 5216786.

Almost surely, 2^20867138 is an apocalyptic number.

20867138 is a deficient number, since it is larger than the sum of its proper divisors (10433572).

20867138 is a wasteful number, since it uses less digits than its factorization.

20867138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10433571.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 20867138 is about 4568.0562605992. The cubic root of 20867138 is about 275.3093510501.

The spelling of 20867138 in words is "twenty million, eight hundred sixty-seven thousand, one hundred thirty-eight".