20804161728 has 56 divisors (see below), whose sum is σ = 62907826432. Its totient is φ = 5944045824.

The previous prime is 20804161711. The next prime is 20804161747. The reversal of 20804161728 is 82716140802.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (56).

It is an unprimeable number.

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, 7738300 + ... + 7740987.

Almost surely, 2^20804161728 is an apocalyptic number.

20804161728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20804161728 is an abundant number, since it is smaller than the sum of its proper divisors (42103664704).

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

20804161728 is a wasteful number, since it uses less digits than its factorization.

20804161728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15479309 (or 15479299 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 39.

The spelling of 20804161728 in words is "twenty billion, eight hundred four million, one hundred sixty-one thousand, seven hundred twenty-eight".