20656417 has 4 divisors (see below), whose sum is σ = 20666800. Its totient is φ = 20646036.

The previous prime is 20656409. The next prime is 20656429. The reversal of 20656417 is 71465602.

It is a happy number.

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 20656417 - 2³ = 20656409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20656117) 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 in 3 ways as a sum of consecutive naturals, for example, 1167 + ... + 6532.

It is an arithmetic number, because the mean of its divisors is an integer number (5166700).

Almost surely, 2^20656417 is an apocalyptic number.

It is an amenable number.

20656417 is a deficient number, since it is larger than the sum of its proper divisors (10383).

20656417 is an equidigital number, since it uses as much as digits as its factorization.

20656417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10382.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 20656417 is about 4544.9331128192. The cubic root of 20656417 is about 274.3795023675.

The spelling of 20656417 in words is "twenty million, six hundred fifty-six thousand, four hundred seventeen".