20566872 has 80 divisors (see below), whose sum is σ = 61027560. Its totient is φ = 6448896.

The previous prime is 20566867. The next prime is 20566877. The reversal of 20566872 is 27866502.

20566872 is a `hidden beast` number, since 20 + 566 + 8 + 72 = 666.

It is an interprime number because it is at equal distance from previous prime (20566867) and next prime (20566877).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20566877) 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 19 ways as a sum of consecutive naturals, for example, 10083 + ... + 11949.

Almost surely, 2^20566872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20566872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30513780).

20566872 is an abundant number, since it is smaller than the sum of its proper divisors (40460688).

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

20566872 is a wasteful number, since it uses less digits than its factorization.

20566872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1902 (or 1889 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 20566872 is about 4535.0713335073. The cubic root of 20566872 is about 273.9824522124.

The spelling of 20566872 in words is "twenty million, five hundred sixty-six thousand, eight hundred seventy-two".