813640964 has 24 divisors (see below), whose sum is σ = 1442336280. Its totient is φ = 401573376.

The previous prime is 813640943. The next prime is 813640979. The reversal of 813640964 is 469046318.

It can be written as a sum of positive squares in 4 ways, for example, as 80856064 + 732784900 = 8992^2 + 27070^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117404 + ... + 124140.

It is an arithmetic number, because the mean of its divisors is an integer number (60097345).

Almost surely, 2^813640964 is an apocalyptic number.

It is an amenable number.

813640964 is a deficient number, since it is larger than the sum of its proper divisors (628695316).

813640964 is a wasteful number, since it uses less digits than its factorization.

813640964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7127 (or 7125 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 41.

The square root of 813640964 is about 28524.3924387532. The cubic root of 813640964 is about 933.5643706388.

The spelling of 813640964 in words is "eight hundred thirteen million, six hundred forty thousand, nine hundred sixty-four".