1891384640 has 224 divisors, whose sum is σ = 5201107200. Its totient is φ = 650280960.

The previous prime is 1891384631. The next prime is 1891384673. The reversal of 1891384640 is 464831981.

It is a junction number, because it is equal to n+sod(n) for n = 1891384591 and 1891384600.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2997125 + ... + 2997755.

Almost surely, 2^1891384640 is an apocalyptic number.

1891384640 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 1891384640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2600553600).

1891384640 is an abundant number, since it is smaller than the sum of its proper divisors (3309722560).

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

1891384640 is a wasteful number, since it uses less digits than its factorization.

1891384640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 713 (or 703 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 44.

The square root of 1891384640 is about 43490.0521958758. The cubic root of 1891384640 is about 1236.6874472702.

The spelling of 1891384640 in words is "one billion, eight hundred ninety-one million, three hundred eighty-four thousand, six hundred forty".