20671872 has 128 divisors (see below), whose sum is σ = 61175520. Its totient is φ = 6144000.

The previous prime is 20671817. The next prime is 20671873. The reversal of 20671872 is 27817602.

It is a tau number, because it is divible by the number of its divisors (128).

It is a zygodrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20671873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 204622 + ... + 204722.

Almost surely, 2^20671872 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 20671872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30587760).

20671872 is an abundant number, since it is smaller than the sum of its proper divisors (40503648).

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

20671872 is a wasteful number, since it uses less digits than its factorization.

20671872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 160 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 33.

The square root of 20671872 is about 4546.6330399539. The cubic root of 20671872 is about 274.4479149753.

The spelling of 20671872 in words is "twenty million, six hundred seventy-one thousand, eight hundred seventy-two".