809423640 has 384 divisors, whose sum is σ = 2924812800. Its totient is φ = 193536000.

The previous prime is 809423569. The next prime is 809423647. The reversal of 809423640 is 46324908.

It is a happy number.

809423640 is a `hidden beast` number, since 8 + 0 + 9 + 4 + 2 + 3 + 640 = 666.

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 = 809423595 and 809423604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809423647) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 13269210 + ... + 13269270.

It is an arithmetic number, because the mean of its divisors is an integer number (7616700).

Almost surely, 2^809423640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 809423640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1462406400).

809423640 is an abundant number, since it is smaller than the sum of its proper divisors (2115389160).

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

809423640 is a wasteful number, since it uses less digits than its factorization.

809423640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 809423640 is about 28450.3715265724. The cubic root of 809423640 is about 931.9486024693.

It can be divided in two parts, 8094236 and 40, that added together give a triangular number (8094276 = T₄₀₂₃).

The spelling of 809423640 in words is "eight hundred nine million, four hundred twenty-three thousand, six hundred forty".