812128420 has 24 divisors (see below), whose sum is σ = 1805792184. Its totient is φ = 305742336.

The previous prime is 812128409. The next prime is 812128469. The reversal of 812128420 is 24821218.

It can be written as a sum of positive squares in 4 ways, for example, as 383141476 + 428986944 = 19574^2 + 20712^2 .

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, 1193967 + ... + 1194646.

It is an arithmetic number, because the mean of its divisors is an integer number (75241341).

Almost surely, 2^812128420 is an apocalyptic number.

It is an amenable number.

812128420 is an abundant number, since it is smaller than the sum of its proper divisors (993663764).

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

812128420 is a wasteful number, since it uses less digits than its factorization.

812128420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2388639 (or 2388637 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 28.

The square root of 812128420 is about 28497.8669377201. The cubic root of 812128420 is about 932.9855186426.

Adding to 812128420 its reverse (24821218), we get a palindrome (836949638).

The spelling of 812128420 in words is "eight hundred twelve million, one hundred twenty-eight thousand, four hundred twenty".