1581115228 has 72 divisors (see below), whose sum is σ = 3570064736. Its totient is φ = 599322240.

The previous prime is 1581115213. The next prime is 1581115231. The reversal of 1581115228 is 8225111851.

It is a happy number.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1581115193 and 1581115202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 119050 + ... + 131662.

Almost surely, 2^1581115228 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 1581115228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1785032368).

1581115228 is an abundant number, since it is smaller than the sum of its proper divisors (1988949508).

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

1581115228 is a wasteful number, since it uses less digits than its factorization.

1581115228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12683 (or 12670 counting only the distinct ones).

The product of its digits is 6400, while the sum is 34.

The square root of 1581115228 is about 39763.2396567483. The cubic root of 1581115228 is about 1164.9872540004.

The spelling of 1581115228 in words is "one billion, five hundred eighty-one million, one hundred fifteen thousand, two hundred twenty-eight".