817331940 has 72 divisors (see below), whose sum is σ = 2564747640. Its totient is φ = 210438144.

The previous prime is 817331939. The next prime is 817331953. The reversal of 817331940 is 49133718.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 23444964 + 793886976 = 4842^2 + 28176^2 .

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 = 817331895 and 817331904.

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, 73069 + ... + 83508.

It is an arithmetic number, because the mean of its divisors is an integer number (35621495).

Almost surely, 2^817331940 is an apocalyptic number.

It is an amenable number.

817331940 is an abundant number, since it is smaller than the sum of its proper divisors (1747415700).

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

817331940 is a wasteful number, since it uses less digits than its factorization.

817331940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156621 (or 156616 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 817331940 is about 28589.0178215342. The cubic root of 817331940 is about 934.9739056841.

The spelling of 817331940 in words is "eight hundred seventeen million, three hundred thirty-one thousand, nine hundred forty".