1813651840 has 512 divisors, whose sum is σ = 6168960000. Its totient is φ = 491028480.

The previous prime is 1813651823. The next prime is 1813651907. The reversal of 1813651840 is 481563181.

It is a self number, because there is not a number n which added to its sum of digits gives 1813651840.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12172086 + ... + 12172234.

It is an arithmetic number, because the mean of its divisors is an integer number (12048750).

Almost surely, 2^1813651840 is an apocalyptic number.

1813651840 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 1813651840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3084480000).

1813651840 is an abundant number, since it is smaller than the sum of its proper divisors (4355308160).

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

1813651840 is a wasteful number, since it uses less digits than its factorization.

1813651840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 1813651840 is about 42586.9914410492. The cubic root of 1813651840 is about 1219.5079624719.

The spelling of 1813651840 in words is "one billion, eight hundred thirteen million, six hundred fifty-one thousand, eight hundred forty".