813681280 has 64 divisors (see below), whose sum is σ = 1956717000. Its totient is φ = 323547136.

The previous prime is 813681259. The next prime is 813681283. The reversal of 813681280 is 82186318.

It can be written as a sum of positive squares in 4 ways, for example, as 800663616 + 13017664 = 28296^2 + 3608^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (813681283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107046 + ... + 114394.

Almost surely, 2^813681280 is an apocalyptic number.

813681280 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 813681280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (978358500).

813681280 is an abundant number, since it is smaller than the sum of its proper divisors (1143035720).

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

813681280 is a wasteful number, since it uses less digits than its factorization.

813681280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7541 (or 7529 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 37.

The square root of 813681280 is about 28525.0991234036. The cubic root of 813681280 is about 933.5797897901.

The spelling of 813681280 in words is "eight hundred thirteen million, six hundred eighty-one thousand, two hundred eighty".