20405312056 has 16 divisors (see below), whose sum is σ = 38348326800. Its totient is φ = 10179091584.

The previous prime is 20405312023. The next prime is 20405312069. The reversal of 20405312056 is 65021350402.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 2941876 + ... + 2948803.

It is an arithmetic number, because the mean of its divisors is an integer number (2396770425).

Almost surely, 2^20405312056 is an apocalyptic number.

It is an amenable number.

20405312056 is a deficient number, since it is larger than the sum of its proper divisors (17943014744).

20405312056 is a wasteful number, since it uses less digits than its factorization.

20405312056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5891118 (or 5891114 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 20405312056 its reverse (65021350402), we get a palindrome (85426662458).

The spelling of 20405312056 in words is "twenty billion, four hundred five million, three hundred twelve thousand, fifty-six".