20906144 has 72 divisors (see below), whose sum is σ = 48837600. Its totient is φ = 8781696.

The previous prime is 20906143. The next prime is 20906153. The reversal of 20906144 is 44160902.

It is not an unprimeable number, because it can be changed into a prime (20906143) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 104957 + ... + 105155.

It is an arithmetic number, because the mean of its divisors is an integer number (678300).

Almost surely, 2^20906144 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 20906144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24418800).

20906144 is an abundant number, since it is smaller than the sum of its proper divisors (27931456).

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

20906144 is a wasteful number, since it uses less digits than its factorization.

20906144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290 (or 275 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 20906144 is about 4572.3236980774. The cubic root of 20906144 is about 275.4807853943.

The spelling of 20906144 in words is "twenty million, nine hundred six thousand, one hundred forty-four".