20855656215 has 24 divisors (see below), whose sum is σ = 36153235248. Its totient is φ = 11121960960.

The previous prime is 20855656189. The next prime is 20855656267. The reversal of 20855656215 is 51265655802.

20855656215 is a `hidden beast` number, since 2 + 0 + 85 + 5 + 6 + 562 + 1 + 5 = 666.

It is not a de Polignac number, because 20855656215 - 2⁸ = 20855655959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 773847 + ... + 800343.

It is an arithmetic number, because the mean of its divisors is an integer number (1506384802).

Almost surely, 2^20855656215 is an apocalyptic number.

20855656215 is a deficient number, since it is larger than the sum of its proper divisors (15297579033).

20855656215 is a wasteful number, since it uses less digits than its factorization.

20855656215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43999 (or 43996 counting only the distinct ones).

The product of its (nonzero) digits is 720000, while the sum is 45.

The spelling of 20855656215 in words is "twenty billion, eight hundred fifty-five million, six hundred fifty-six thousand, two hundred fifteen".