806509440 has 256 divisors, whose sum is σ = 3116793600. Its totient is φ = 195471360.

The previous prime is 806509399. The next prime is 806509447. The reversal of 806509440 is 44905608.

It is a super-2 number, since 2×806509440² = 1300914953618227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 806509395 and 806509404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (806509447) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 187959 + ... + 192201.

It is an arithmetic number, because the mean of its divisors is an integer number (12174975).

Almost surely, 2^806509440 is an apocalyptic number.

806509440 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 806509440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1558396800).

806509440 is an abundant number, since it is smaller than the sum of its proper divisors (2310284160).

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

806509440 is a wasteful number, since it uses less digits than its factorization.

806509440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4282 (or 4264 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 806509440 is about 28399.1098452047. The cubic root of 806509440 is about 930.8288136933.

The spelling of 806509440 in words is "eight hundred six million, five hundred nine thousand, four hundred forty".