1881584640 has 440 divisors, whose sum is σ = 7281997800. Its totient is φ = 461832192.

The previous prime is 1881584623. The next prime is 1881584681. The reversal of 1881584640 is 464851881.

1881584640 is a `hidden beast` number, since 1 + 8 + 8 + 1 + 584 + 64 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 113550336 + 1768034304 = 10656^2 + 42048^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5391186 + ... + 5391534.

It is an arithmetic number, because the mean of its divisors is an integer number (16549995).

Almost surely, 2^1881584640 is an apocalyptic number.

1881584640 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 1881584640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3640998900).

1881584640 is an abundant number, since it is smaller than the sum of its proper divisors (5400413160).

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

1881584640 is a wasteful number, since it uses less digits than its factorization.

1881584640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399 (or 372 counting only the distinct ones).

The product of its (nonzero) digits is 245760, while the sum is 45.

The square root of 1881584640 is about 43377.2364264945. The cubic root of 1881584640 is about 1234.5478279313.

The spelling of 1881584640 in words is "one billion, eight hundred eighty-one million, five hundred eighty-four thousand, six hundred forty".