20556217000 has 64 divisors (see below), whose sum is σ = 52474443840. Its totient is φ = 7474984000.

The previous prime is 20556216973. The next prime is 20556217013. The reversal of 20556217000 is 71265502.

It is a self number, because there is not a number n which added to its sum of digits gives 20556217000.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 923374 + ... + 945373.

It is an arithmetic number, because the mean of its divisors is an integer number (819913185).

Almost surely, 2^20556217000 is an apocalyptic number.

20556217000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20556217000 is an abundant number, since it is smaller than the sum of its proper divisors (31918226840).

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

20556217000 is a wasteful number, since it uses less digits than its factorization.

20556217000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1868779 (or 1868765 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 28.

The spelling of 20556217000 in words is "twenty billion, five hundred fifty-six million, two hundred seventeen thousand".