20556717140 has 24 divisors (see below), whose sum is σ = 43207594080. Its totient is φ = 8215355808.

The previous prime is 20556717121. The next prime is 20556717151. The reversal of 20556717140 is 4171765502.

It is a junction number, because it is equal to n+sod(n) for n = 20556717094 and 20556717103.

It is a congruent number.

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, 435170 + ... + 480089.

It is an arithmetic number, because the mean of its divisors is an integer number (1800316420).

Almost surely, 2^20556717140 is an apocalyptic number.

20556717140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20556717140 is an abundant number, since it is smaller than the sum of its proper divisors (22650876940).

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

20556717140 is a wasteful number, since it uses less digits than its factorization.

20556717140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916391 (or 916389 counting only the distinct ones).

The product of its (nonzero) digits is 58800, while the sum is 38.

The spelling of 20556717140 in words is "twenty billion, five hundred fifty-six million, seven hundred seventeen thousand, one hundred forty".