20661017 has 8 divisors (see below), whose sum is σ = 22338624. Its totient is φ = 18996048.

The previous prime is 20661013. The next prime is 20661019. The reversal of 20661017 is 71016602.

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 20661017 - 2² = 20661013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20660983 and 20661001.

It is not an unprimeable number, because it can be changed into a prime (20661013) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 398 + ... + 6440.

It is an arithmetic number, because the mean of its divisors is an integer number (2792328).

Almost surely, 2^20661017 is an apocalyptic number.

It is an amenable number.

20661017 is a deficient number, since it is larger than the sum of its proper divisors (1677607).

20661017 is a wasteful number, since it uses less digits than its factorization.

20661017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6319.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 20661017 is about 4545.4391427012. The cubic root of 20661017 is about 274.3998681459.

Adding to 20661017 its reverse (71016602), we get a palindrome (91677619).

The spelling of 20661017 in words is "twenty million, six hundred sixty-one thousand, seventeen".