809951940 has 288 divisors, whose sum is σ = 2972739840. Its totient is φ = 179324928.

The previous prime is 809951939. The next prime is 809951953. The reversal of 809951940 is 49159908.

809951940 is a `hidden beast` number, since 8 + 0 + 99 + 519 + 40 = 666.

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 95 ways as a sum of consecutive naturals, for example, 8349972 + ... + 8350068.

Almost surely, 2^809951940 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 809951940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1486369920).

809951940 is an abundant number, since it is smaller than the sum of its proper divisors (2162787900).

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

809951940 is a wasteful number, since it uses less digits than its factorization.

809951940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The square root of 809951940 is about 28459.6546008556. The cubic root of 809951940 is about 932.1513151753.

The spelling of 809951940 in words is "eight hundred nine million, nine hundred fifty-one thousand, nine hundred forty".