20978112 has 56 divisors (see below), whose sum is σ = 57024016. Its totient is φ = 6801408.

The previous prime is 20978077. The next prime is 20978117. The reversal of 20978112 is 21187902.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 20978112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20978117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5628 + ... + 8580.

It is an arithmetic number, because the mean of its divisors is an integer number (1018286).

Almost surely, 2^20978112 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 20978112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28512008).

20978112 is an abundant number, since it is smaller than the sum of its proper divisors (36045904).

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

20978112 is a wasteful number, since it uses less digits than its factorization.

20978112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3005 (or 2995 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 20978112 is about 4580.1868957500. The cubic root of 20978112 is about 275.7965314082.

The spelling of 20978112 in words is "twenty million, nine hundred seventy-eight thousand, one hundred twelve".