809129918340 has 72 divisors (see below), whose sum is σ = 2476877883480. Its totient is φ = 213788450304.

The previous prime is 809129918329. The next prime is 809129918347. The reversal of 809129918340 is 43819921908.

809129918340 is a `hidden beast` number, since 8 + 0 + 9 + 1 + 299 + 1 + 8 + 340 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 415970821764 + 393159096576 = 644958^2 + 627024^2 .

It is not an unprimeable number, because it can be changed into a prime (809129918347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20600409 + ... + 20639648.

It is an arithmetic number, because the mean of its divisors is an integer number (34401081715).

Almost surely, 2^809129918340 is an apocalyptic number.

It is an amenable number.

809129918340 is an abundant number, since it is smaller than the sum of its proper divisors (1667747965140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

809129918340 is a wasteful number, since it uses less digits than its factorization.

809129918340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41240181 (or 41240176 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 809129918340 in words is "eight hundred nine billion, one hundred twenty-nine million, nine hundred eighteen thousand, three hundred forty".