20391248 has 20 divisors (see below), whose sum is σ = 41226528. Its totient is φ = 9752160.

The previous prime is 20391229. The next prime is 20391257. The reversal of 20391248 is 84219302.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 20391248.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27338 + ... + 28073.

Almost surely, 2^20391248 is an apocalyptic number.

It is an amenable number.

20391248 is an abundant number, since it is smaller than the sum of its proper divisors (20835280).

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

20391248 is a wasteful number, since it uses less digits than its factorization.

20391248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55442 (or 55436 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 20391248 is about 4515.6669496321. Note that the first 3 decimals coincide. The cubic root of 20391248 is about 273.2003609941.

The spelling of 20391248 in words is "twenty million, three hundred ninety-one thousand, two hundred forty-eight".