20906617 has 8 divisors (see below), whose sum is σ = 22851072. Its totient is φ = 19041600.

The previous prime is 20906581. The next prime is 20906629. The reversal of 20906617 is 71660902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20906617 - 2⁷ = 20906489 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20906647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19309 + ... + 20362.

It is an arithmetic number, because the mean of its divisors is an integer number (2856384).

Almost surely, 2^20906617 is an apocalyptic number.

It is an amenable number.

20906617 is a deficient number, since it is larger than the sum of its proper divisors (1944455).

20906617 is a wasteful number, since it uses less digits than its factorization.

20906617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39719.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 20906617 is about 4572.3754220317. The cubic root of 20906617 is about 275.4828629562.

The spelling of 20906617 in words is "twenty million, nine hundred six thousand, six hundred seventeen".