1820339640 has 384 divisors, whose sum is σ = 7027637760. Its totient is φ = 400038912.

The previous prime is 1820339639. The next prime is 1820339671. The reversal of 1820339640 is 469330281.

1820339640 is a `hidden beast` number, since 1 + 8 + 2 + 0 + 3 + 3 + 9 + 640 = 666.

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 = 1820339595 and 1820339604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11594442 + ... + 11594598.

It is an arithmetic number, because the mean of its divisors is an integer number (18301140).

Almost surely, 2^1820339640 is an apocalyptic number.

1820339640 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 1820339640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3513818880).

1820339640 is an abundant number, since it is smaller than the sum of its proper divisors (5207298120).

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

1820339640 is a wasteful number, since it uses less digits than its factorization.

1820339640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331 (or 324 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 1820339640 is about 42665.4384719060. The cubic root of 1820339640 is about 1221.0050930772.

The spelling of 1820339640 in words is "one billion, eight hundred twenty million, three hundred thirty-nine thousand, six hundred forty".