806122457991 has 20 divisors (see below), whose sum is σ = 1267586973400. Its totient is φ = 509129972496.

The previous prime is 806122457971. The next prime is 806122458007. The reversal of 806122457991 is 199754221608.

It is a happy number.

806122457991 is a `hidden beast` number, since 8 + 0 + 61 + 2 + 2 + 4 + 579 + 9 + 1 = 666.

806122457991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 806122457991 - 2⁷ = 806122457863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (806122457911) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 261896596 + ... + 261899673.

It is an arithmetic number, because the mean of its divisors is an integer number (63379348670).

Almost surely, 2^806122457991 is an apocalyptic number.

806122457991 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

806122457991 is a deficient number, since it is larger than the sum of its proper divisors (461464515409).

806122457991 is a wasteful number, since it uses less digits than its factorization.

806122457991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523796300 (or 523796291 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 54.

The spelling of 806122457991 in words is "eight hundred six billion, one hundred twenty-two million, four hundred fifty-seven thousand, nine hundred ninety-one".