20185904 has 40 divisors (see below), whose sum is σ = 42973440. Its totient is φ = 9142848.

The previous prime is 20185883. The next prime is 20185967. The reversal of 20185904 is 40958102.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5549 + ... + 8435.

It is an arithmetic number, because the mean of its divisors is an integer number (1074336).

Almost surely, 2^20185904 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 20185904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21486720).

20185904 is an abundant number, since it is smaller than the sum of its proper divisors (22787536).

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

20185904 is a wasteful number, since it uses less digits than its factorization.

20185904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2937 (or 2931 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 20185904 is about 4492.8725777614. The cubic root of 20185904 is about 272.2802043243.

The spelling of 20185904 in words is "twenty million, one hundred eighty-five thousand, nine hundred four".