20855986823 has 16 divisors (see below), whose sum is σ = 25100160000. Its totient is φ = 16928769312.

The previous prime is 20855986817. The next prime is 20855986843. The reversal of 20855986823 is 32868955802.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-20855986823 is a prime.

It is a super-2 number, since 2×20855986823² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20855986813) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 308258 + ... + 369776.

It is an arithmetic number, because the mean of its divisors is an integer number (1568760000).

Almost surely, 2^20855986823 is an apocalyptic number.

20855986823 is a deficient number, since it is larger than the sum of its proper divisors (4244173177).

20855986823 is a wasteful number, since it uses less digits than its factorization.

20855986823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64094.

The product of its (nonzero) digits is 8294400, while the sum is 56.

The spelling of 20855986823 in words is "twenty billion, eight hundred fifty-five million, nine hundred eighty-six thousand, eight hundred twenty-three".