20905339 has 32 divisors (see below), whose sum is σ = 27578880. Its totient is φ = 15386112.

The previous prime is 20905337. The next prime is 20905349. The reversal of 20905339 is 93350902.

It is not a de Polignac number, because 20905339 - 2¹ = 20905337 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20905339.

It is not an unprimeable number, because it can be changed into a prime (20905331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 184947 + ... + 185059.

It is an arithmetic number, because the mean of its divisors is an integer number (861840).

Almost surely, 2^20905339 is an apocalyptic number.

20905339 is a deficient number, since it is larger than the sum of its proper divisors (6673541).

20905339 is a wasteful number, since it uses less digits than its factorization.

20905339 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259.

The product of its (nonzero) digits is 7290, while the sum is 31.

The square root of 20905339 is about 4572.2356675919. The cubic root of 20905339 is about 275.4772495138.

The spelling of 20905339 in words is "twenty million, nine hundred five thousand, three hundred thirty-nine".