3966021840 has 240 divisors, whose sum is σ = 13847738688. Its totient is φ = 937728000.

The previous prime is 3966021803. The next prime is 3966021847. The reversal of 3966021840 is 481206693.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3966021847) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1188975 + ... + 1192305.

Almost surely, 2^3966021840 is an apocalyptic number.

3966021840 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 3966021840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6923869344).

3966021840 is an abundant number, since it is smaller than the sum of its proper divisors (9881716848).

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

3966021840 is a wasteful number, since it uses less digits than its factorization.

3966021840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3410 (or 3393 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 3966021840 is about 62976.3593739746. The cubic root of 3966021840 is about 1582.8935173844.

The spelling of 3966021840 in words is "three billion, nine hundred sixty-six million, twenty-one thousand, eight hundred forty".