39965981328 has 480 divisors, whose sum is σ = 142720032000. Its totient is φ = 10371981312.

The previous prime is 39965981291. The next prime is 39965981329. The reversal of 39965981328 is 82318956993.

39965981328 is a `hidden beast` number, since 3 + 9 + 9 + 6 + 598 + 1 + 32 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39965981329) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 43019968 + ... + 43020896.

It is an arithmetic number, because the mean of its divisors is an integer number (297333400).

Almost surely, 2^39965981328 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 39965981328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71360016000).

39965981328 is an abundant number, since it is smaller than the sum of its proper divisors (102754050672).

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

39965981328 is a wasteful number, since it uses less digits than its factorization.

39965981328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1044 (or 1021 counting only the distinct ones).

The product of its digits is 25194240, while the sum is 63.

The spelling of 39965981328 in words is "thirty-nine billion, nine hundred sixty-five million, nine hundred eighty-one thousand, three hundred twenty-eight".