20813663806 has 24 divisors (see below), whose sum is σ = 33866536320. Its totient is φ = 9589334976.

The previous prime is 20813663803. The next prime is 20813663809. The reversal of 20813663806 is 60836631802.

It is an interprime number because it is at equal distance from previous prime (20813663803) and next prime (20813663809).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20813663803) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 138211 + ... + 246433.

It is an arithmetic number, because the mean of its divisors is an integer number (1411105680).

Almost surely, 2^20813663806 is an apocalyptic number.

20813663806 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20813663806 is a deficient number, since it is larger than the sum of its proper divisors (13052872514).

20813663806 is a wasteful number, since it uses less digits than its factorization.

20813663806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108820 (or 108807 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 43.

The spelling of 20813663806 in words is "twenty billion, eight hundred thirteen million, six hundred sixty-three thousand, eight hundred six".