1813229640 has 288 divisors, whose sum is σ = 6273394920. Its totient is φ = 453992448.

The previous prime is 1813229629. The next prime is 1813229647. The reversal of 1813229640 is 469223181.

1813229640 is a `hidden beast` number, since 1 + 8 + 1 + 3 + 2 + 2 + 9 + 640 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 32558436 + 1780671204 = 5706^2 + 42198^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1813229595 and 1813229604.

It is not an unprimeable number, because it can be changed into a prime (1813229647) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 16046224 + ... + 16046336.

Almost surely, 2^1813229640 is an apocalyptic number.

1813229640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1813229640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3136697460).

1813229640 is an abundant number, since it is smaller than the sum of its proper divisors (4460165280).

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

1813229640 is a wasteful number, since it uses less digits than its factorization.

1813229640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 1813229640 is about 42582.0342398059. The cubic root of 1813229640 is about 1219.4133253778.

The spelling of 1813229640 in words is "one billion, eight hundred thirteen million, two hundred twenty-nine thousand, six hundred forty".