3967647840 has 768 divisors, whose sum is σ = 16094453760. Its totient is φ = 905748480.

The previous prime is 3967647839. The next prime is 3967647869. The reversal of 3967647840 is 487467693.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 74861254 + ... + 74861306.

It is an arithmetic number, because the mean of its divisors is an integer number (20956320).

Almost surely, 2^3967647840 is an apocalyptic number.

3967647840 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 3967647840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8047226880).

3967647840 is an abundant number, since it is smaller than the sum of its proper divisors (12126805920).

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

3967647840 is a wasteful number, since it uses less digits than its factorization.

3967647840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 6096384, while the sum is 54.

The square root of 3967647840 is about 62989.2676572763. The cubic root of 3967647840 is about 1583.1098074358.

The spelling of 3967647840 in words is "three billion, nine hundred sixty-seven million, six hundred forty-seven thousand, eight hundred forty".