1813640988 has 192 divisors, whose sum is σ = 4971552768. Its totient is φ = 510935040.

The previous prime is 1813640821. The next prime is 1813641007. The reversal of 1813640988 is 8890463181.

It is a super-2 number, since 2×1813640988² = 6578587266707232288, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5381556 + ... + 5381892.

It is an arithmetic number, because the mean of its divisors is an integer number (25893504).

Almost surely, 2^1813640988 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 1813640988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2485776384).

1813640988 is an abundant number, since it is smaller than the sum of its proper divisors (3157911780).

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

1813640988 is a wasteful number, since it uses less digits than its factorization.

1813640988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452 (or 450 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 48.

The square root of 1813640988 is about 42586.8640310601. The cubic root of 1813640988 is about 1219.5055301553.

The spelling of 1813640988 in words is "one billion, eight hundred thirteen million, six hundred forty thousand, nine hundred eighty-eight".