20971872 has 168 divisors, whose sum is σ = 66104640. Its totient is φ = 6531840.

The previous prime is 20971807. The next prime is 20971889. The reversal of 20971872 is 27817902.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 676497 + ... + 676527.

It is an arithmetic number, because the mean of its divisors is an integer number (393480).

Almost surely, 2^20971872 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 20971872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33052320).

20971872 is an abundant number, since it is smaller than the sum of its proper divisors (45132768).

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

20971872 is an equidigital number, since it uses as much as digits as its factorization.

20971872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 20971872 is about 4579.5056501767. The cubic root of 20971872 is about 275.7691832049.

It can be divided in two parts, 2097 and 1872, that added together give a square (3969 = 63²).

The spelling of 20971872 in words is "twenty million, nine hundred seventy-one thousand, eight hundred seventy-two".