20904842 has 16 divisors (see below), whose sum is σ = 35895552. Its totient is φ = 8944560.

The previous prime is 20904839. The next prime is 20904847. The reversal of 20904842 is 24840902.

It is not an unprimeable number, because it can be changed into a prime (20904847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16367 + ... + 17597.

It is an arithmetic number, because the mean of its divisors is an integer number (2243472).

Almost surely, 2^20904842 is an apocalyptic number.

20904842 is a deficient number, since it is larger than the sum of its proper divisors (14990710).

20904842 is a wasteful number, since it uses less digits than its factorization.

20904842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2453.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 20904842 is about 4572.1813174895. The cubic root of 20904842 is about 275.4750664466.

The spelling of 20904842 in words is "twenty million, nine hundred four thousand, eight hundred forty-two".