20806455806 has 16 divisors (see below), whose sum is σ = 31540564080. Its totient is φ = 10293176640.

The previous prime is 20806455781. The next prime is 20806455821. The reversal of 20806455806 is 60855460802.

It is a super-2 number, since 2×20806455806² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 113036 + ... + 233216.

It is an arithmetic number, because the mean of its divisors is an integer number (1971285255).

Almost surely, 2^20806455806 is an apocalyptic number.

20806455806 is a deficient number, since it is larger than the sum of its proper divisors (10734108274).

20806455806 is a wasteful number, since it uses less digits than its factorization.

20806455806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121099.

The product of its (nonzero) digits is 460800, while the sum is 44.

The spelling of 20806455806 in words is "twenty billion, eight hundred six million, four hundred fifty-five thousand, eight hundred six".