813725640 has 384 divisors, whose sum is σ = 3317932800. Its totient is φ = 168376320.

The previous prime is 813725629. The next prime is 813725663. The reversal of 813725640 is 46527318.

813725640 is a `hidden beast` number, since 8 + 1 + 3 + 7 + 2 + 5 + 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 = 813725595 and 813725604.

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, 1932630 + ... + 1933050.

It is an arithmetic number, because the mean of its divisors is an integer number (8640450).

Almost surely, 2^813725640 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 813725640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1658966400).

813725640 is an abundant number, since it is smaller than the sum of its proper divisors (2504207160).

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

813725640 is a wasteful number, since it uses less digits than its factorization.

813725640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 813725640 is about 28525.8766736449. The cubic root of 813725640 is about 933.5967550106.

The spelling of 813725640 in words is "eight hundred thirteen million, seven hundred twenty-five thousand, six hundred forty".