815256220428 has 144 divisors (see below), whose sum is σ = 2250537307200. Its totient is φ = 247334123520.

The previous prime is 815256220423. The next prime is 815256220481. The reversal of 815256220428 is 824022652518.

815256220428 is a `hidden beast` number, since 8 + 1 + 525 + 62 + 20 + 42 + 8 = 666.

815256220428 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (815256220423) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14925808 + ... + 14980328.

It is an arithmetic number, because the mean of its divisors is an integer number (15628731300).

Almost surely, 2^815256220428 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 815256220428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1125268653600).

815256220428 is an abundant number, since it is smaller than the sum of its proper divisors (1435281086772).

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

815256220428 is a wasteful number, since it uses less digits than its factorization.

815256220428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54992 (or 54987 counting only the distinct ones).

The product of its (nonzero) digits is 614400, while the sum is 45.

The spelling of 815256220428 in words is "eight hundred fifteen billion, two hundred fifty-six million, two hundred twenty thousand, four hundred twenty-eight".