39968691840 has 2560 divisors, whose sum is σ = 204738969600. Its totient is φ = 7166361600.

The previous prime is 39968691827. The next prime is 39968691913. The reversal of 39968691840 is 4819686993.

It is a happy number.

39968691840 is a `hidden beast` number, since 399 + 6 + 8 + 69 + 184 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 1289312625 + ... + 1289312655.

It is an arithmetic number, because the mean of its divisors is an integer number (79976160).

Almost surely, 2^39968691840 is an apocalyptic number.

39968691840 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 39968691840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102369484800).

39968691840 is an abundant number, since it is smaller than the sum of its proper divisors (164770277760).

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

39968691840 is a wasteful number, since it uses less digits than its factorization.

39968691840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 20155392, while the sum is 63.

The spelling of 39968691840 in words is "thirty-nine billion, nine hundred sixty-eight million, six hundred ninety-one thousand, eight hundred forty".