20101566 has 8 divisors (see below), whose sum is σ = 40203144. Its totient is φ = 6700520.

The previous prime is 20101561. The next prime is 20101577. The reversal of 20101566 is 66510102.

It is a happy number.

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

20101566 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101561) 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, 1675125 + ... + 1675136.

It is an arithmetic number, because the mean of its divisors is an integer number (5025393).

Almost surely, 2^20101566 is an apocalyptic number.

20101566 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20101566 is a wasteful number, since it uses less digits than its factorization.

20101566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3350266.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 20101566 is about 4483.4769989373. The cubic root of 20101566 is about 271.9004736073.

Adding to 20101566 its reverse (66510102), we get a palindrome (86611668).

The spelling of 20101566 in words is "twenty million, one hundred one thousand, five hundred sixty-six".