813461220 has 432 divisors, whose sum is σ = 3110955120. Its totient is φ = 171325440.

The previous prime is 813461213. The next prime is 813461251. The reversal of 813461220 is 22164318.

It can be written as a sum of positive squares in 8 ways, for example, as 500595876 + 312865344 = 22374^2 + 17688^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 47850652 + ... + 47850668.

It is an arithmetic number, because the mean of its divisors is an integer number (7201285).

Almost surely, 2^813461220 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 813461220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1555477560).

813461220 is an abundant number, since it is smaller than the sum of its proper divisors (2297493900).

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

813461220 is a wasteful number, since it uses less digits than its factorization.

813461220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 813461220 is about 28521.2415578284. The cubic root of 813461220 is about 933.4956200228.

The spelling of 813461220 in words is "eight hundred thirteen million, four hundred sixty-one thousand, two hundred twenty".