3994143840 has 144 divisors (see below), whose sum is σ = 13650109200. Its totient is φ = 1063535616.

The previous prime is 3994143817. The next prime is 3994143841. The reversal of 3994143840 is 483414993.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3994143841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1235346 + ... + 1238574.

It is an arithmetic number, because the mean of its divisors is an integer number (94792425).

Almost surely, 2^3994143840 is an apocalyptic number.

3994143840 is a gapful number since it is divisible by the number (30) 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 3994143840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6825054600).

3994143840 is an abundant number, since it is smaller than the sum of its proper divisors (9655965360).

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

3994143840 is a wasteful number, since it uses less digits than its factorization.

3994143840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4109 (or 4098 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 3994143840 is about 63199.2392359275. The cubic root of 3994143840 is about 1586.6260007310.

The spelling of 3994143840 in words is "three billion, nine hundred ninety-four million, one hundred forty-three thousand, eight hundred forty".