20617187 has 4 divisors (see below), whose sum is σ = 20628336. Its totient is φ = 20606040.

The previous prime is 20617151. The next prime is 20617213. The reversal of 20617187 is 78171602.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20617187 - 2⁸ = 20616931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20617127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2063 + ... + 6744.

It is an arithmetic number, because the mean of its divisors is an integer number (5157084).

Almost surely, 2^20617187 is an apocalyptic number.

20617187 is a deficient number, since it is larger than the sum of its proper divisors (11149).

20617187 is an equidigital number, since it uses as much as digits as its factorization.

20617187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11148.

The product of its (nonzero) digits is 4704, while the sum is 32.

The square root of 20617187 is about 4540.6152666792. The cubic root of 20617187 is about 274.2056947281.

Adding to 20617187 its reverse (78171602), we get a palindrome (98788789).

The spelling of 20617187 in words is "twenty million, six hundred seventeen thousand, one hundred eighty-seven".