1992643840 has 144 divisors (see below), whose sum is σ = 5264199360. Its totient is φ = 716636160.

The previous prime is 1992643837. The next prime is 1992643841. The reversal of 1992643840 is 483462991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1992643841) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1365031 + ... + 1366489.

It is an arithmetic number, because the mean of its divisors is an integer number (36556940).

Almost surely, 2^1992643840 is an apocalyptic number.

1992643840 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 1992643840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2632099680).

1992643840 is an abundant number, since it is smaller than the sum of its proper divisors (3271555520).

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

1992643840 is a wasteful number, since it uses less digits than its factorization.

1992643840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1588 (or 1574 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 46.

The square root of 1992643840 is about 44639.0394161882. The cubic root of 1992643840 is about 1258.3744553710.

The spelling of 1992643840 in words is "one billion, nine hundred ninety-two million, six hundred forty-three thousand, eight hundred forty".