20399888 has 40 divisors (see below), whose sum is σ = 40920000. Its totient is φ = 9846144.

The previous prime is 20399887. The next prime is 20399909. The reversal of 20399888 is 88899302.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (20399887) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 102413 + ... + 102611.

It is an arithmetic number, because the mean of its divisors is an integer number (1023000).

Almost surely, 2^20399888 is an apocalyptic number.

It is an amenable number.

20399888 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

20399888 is a wasteful number, since it uses less digits than its factorization.

20399888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399 (or 393 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 47.

The square root of 20399888 is about 4516.6235176291. The cubic root of 20399888 is about 273.2389415625.

The spelling of 20399888 in words is "twenty million, three hundred ninety-nine thousand, eight hundred eighty-eight".