20185138808 has 8 divisors (see below), whose sum is σ = 37847135280. Its totient is φ = 10092569400.

The previous prime is 20185138781. The next prime is 20185138817. The reversal of 20185138808 is 80883158102.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1261571168 + ... + 1261571183.

It is an arithmetic number, because the mean of its divisors is an integer number (4730891910).

Almost surely, 2^20185138808 is an apocalyptic number.

It is an amenable number.

20185138808 is a deficient number, since it is larger than the sum of its proper divisors (17661996472).

20185138808 is a wasteful number, since it uses less digits than its factorization.

20185138808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2523142357 (or 2523142353 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 44.

The spelling of 20185138808 in words is "twenty billion, one hundred eighty-five million, one hundred thirty-eight thousand, eight hundred eight".