809242237440 has 640 divisors, whose sum is σ = 3537868561920. Its totient is φ = 170739892224.

The previous prime is 809242237399. The next prime is 809242237483. The reversal of 809242237440 is 44732242908.

It is a happy number.

809242237440 is a `hidden beast` number, since 80 + 92 + 42 + 2 + 3 + 7 + 440 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

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 63 ways as a sum of consecutive naturals, for example, 6225592 + ... + 6354248.

It is an arithmetic number, because the mean of its divisors is an integer number (5527919628).

Almost surely, 2^809242237440 is an apocalyptic number.

809242237440 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 809242237440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1768934280960).

809242237440 is an abundant number, since it is smaller than the sum of its proper divisors (2728626324480).

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

809242237440 is a wasteful number, since it uses less digits than its factorization.

809242237440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128709 (or 128687 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 45.

The spelling of 809242237440 in words is "eight hundred nine billion, two hundred forty-two million, two hundred thirty-seven thousand, four hundred forty".