1813638540 has 384 divisors, whose sum is σ = 6706022400. Its totient is φ = 356106240.

The previous prime is 1813638487. The next prime is 1813638553. The reversal of 1813638540 is 458363181.

1813638540 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3933910 + ... + 3934370.

It is an arithmetic number, because the mean of its divisors is an integer number (17463600).

Almost surely, 2^1813638540 is an apocalyptic number.

1813638540 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 1813638540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3353011200).

1813638540 is an abundant number, since it is smaller than the sum of its proper divisors (4892383860).

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

1813638540 is a wasteful number, since it uses less digits than its factorization.

1813638540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 545 (or 543 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 39.

The square root of 1813638540 is about 42586.8352897935. The cubic root of 1813638540 is about 1219.5049814706.

The spelling of 1813638540 in words is "one billion, eight hundred thirteen million, six hundred thirty-eight thousand, five hundred forty".