20617717 has 4 divisors (see below), whose sum is σ = 21702880. Its totient is φ = 19532556.

The previous prime is 20617703. The next prime is 20617739. The reversal of 20617717 is 71771602.

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.

It is a cyclic number.

It is not a de Polignac number, because 20617717 - 2¹¹ = 20615669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20617777) 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, 542553 + ... + 542590.

It is an arithmetic number, because the mean of its divisors is an integer number (5425720).

Almost surely, 2^20617717 is an apocalyptic number.

It is an amenable number.

20617717 is a deficient number, since it is larger than the sum of its proper divisors (1085163).

20617717 is a wasteful number, since it uses less digits than its factorization.

20617717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1085162.

The product of its (nonzero) digits is 4116, while the sum is 31.

The square root of 20617717 is about 4540.6736284388. The cubic root of 20617717 is about 274.2080443498.

The spelling of 20617717 in words is "twenty million, six hundred seventeen thousand, seven hundred seventeen".