20642117 has 4 divisors (see below), whose sum is σ = 20652000. Its totient is φ = 20632236.

The previous prime is 20642099. The next prime is 20642129. The reversal of 20642117 is 71124602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, 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 20642117 - 2⁶ = 20642053 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20642092 and 20642101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20642177) 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, 443 + ... + 6440.

It is an arithmetic number, because the mean of its divisors is an integer number (5163000).

Almost surely, 2^20642117 is an apocalyptic number.

It is an amenable number.

20642117 is a deficient number, since it is larger than the sum of its proper divisors (9883).

20642117 is an equidigital number, since it uses as much as digits as its factorization.

20642117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9882.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 20642117 is about 4543.3596599873. The cubic root of 20642117 is about 274.3161720450.

Adding to 20642117 its reverse (71124602), we get a palindrome (91766719).

The spelling of 20642117 in words is "twenty million, six hundred forty-two thousand, one hundred seventeen".