20855656178 has 16 divisors (see below), whose sum is σ = 36183309120. Its totient is φ = 8830449456.

The previous prime is 20855656169. The next prime is 20855656189. The reversal of 20855656178 is 87165655802.

It is a happy number.

It is a super-2 number, since 2×20855656178² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8972873 + ... + 8975196.

It is an arithmetic number, because the mean of its divisors is an integer number (2261456820).

Almost surely, 2^20855656178 is an apocalyptic number.

20855656178 is a deficient number, since it is larger than the sum of its proper divisors (15327652942).

20855656178 is a wasteful number, since it uses less digits than its factorization.

20855656178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17948161.

The product of its (nonzero) digits is 4032000, while the sum is 53.

The spelling of 20855656178 in words is "twenty billion, eight hundred fifty-five million, six hundred fifty-six thousand, one hundred seventy-eight".