805777920 has 240 divisors, whose sum is σ = 2862051192. Its totient is φ = 209387520.

The previous prime is 805777913. The next prime is 805777939. The reversal of 805777920 is 29777508.

805777920 is a `hidden beast` number, since 8 + 0 + 577 + 79 + 2 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 222845184 + 582932736 = 14928^2 + 24144^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 944214 + ... + 945066.

Almost surely, 2^805777920 is an apocalyptic number.

805777920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 805777920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1431025596).

805777920 is an abundant number, since it is smaller than the sum of its proper divisors (2056273272).

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

805777920 is a wasteful number, since it uses less digits than its factorization.

805777920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923 (or 904 counting only the distinct ones).

The product of its (nonzero) digits is 246960, while the sum is 45.

The square root of 805777920 is about 28386.2276465190. The cubic root of 805777920 is about 930.5473018543.

The spelling of 805777920 in words is "eight hundred five million, seven hundred seventy-seven thousand, nine hundred twenty".