813621320 has 32 divisors (see below), whose sum is σ = 1910243520. Its totient is φ = 311298240.

The previous prime is 813621317. The next prime is 813621337. The reversal of 813621320 is 23126318.

It is a self number, because there is not a number n which added to its sum of digits gives 813621320.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 441266 + ... + 443105.

It is an arithmetic number, because the mean of its divisors is an integer number (59695110).

Almost surely, 2^813621320 is an apocalyptic number.

It is an amenable number.

813621320 is an abundant number, since it is smaller than the sum of its proper divisors (1096622200).

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

813621320 is a wasteful number, since it uses less digits than its factorization.

813621320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884405 (or 884401 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 813621320 is about 28524.0480998052. The cubic root of 813621320 is about 933.5568574616.

Adding to 813621320 its reverse (23126318), we get a palindrome (836747638).

The spelling of 813621320 in words is "eight hundred thirteen million, six hundred twenty-one thousand, three hundred twenty".