20163661 has 8 divisors (see below), whose sum is σ = 23129600. Its totient is φ = 17219088.

The previous prime is 20163643. The next prime is 20163697. The reversal of 20163661 is 16636102.

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 20163661 - 2⁵ = 20163629 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 (20163641) 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, 3261 + ... + 7138.

It is an arithmetic number, because the mean of its divisors is an integer number (2891200).

Almost surely, 2^20163661 is an apocalyptic number.

It is an amenable number.

20163661 is a deficient number, since it is larger than the sum of its proper divisors (2965939).

20163661 is a wasteful number, since it uses less digits than its factorization.

20163661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10683.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 20163661 is about 4490.3965303746. The cubic root of 20163661 is about 272.1801583640.

Adding to 20163661 its reverse (16636102), we get a palindrome (36799763).

The spelling of 20163661 in words is "twenty million, one hundred sixty-three thousand, six hundred sixty-one".