39642689856 has 168 divisors, whose sum is σ = 131760610240. Its totient is φ = 10296760320.

The previous prime is 39642689819. The next prime is 39642689873. The reversal of 39642689856 is 65898624693.

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40740 + ... + 284508.

Almost surely, 2^39642689856 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 39642689856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65880305120).

39642689856 is an abundant number, since it is smaller than the sum of its proper divisors (92117920384).

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

39642689856 is a wasteful number, since it uses less digits than its factorization.

39642689856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243813 (or 243792 counting only the distinct ones).

The product of its digits is 134369280, while the sum is 66.

The spelling of 39642689856 in words is "thirty-nine billion, six hundred forty-two million, six hundred eighty-nine thousand, eight hundred fifty-six".