42639994728 has 160 divisors (see below), whose sum is σ = 127371182400. Its totient is φ = 13280537088.

The previous prime is 42639994717. The next prime is 42639994783. The reversal of 42639994728 is 82749993624.

42639994728 is a `hidden beast` number, since 42 + 6 + 39 + 99 + 472 + 8 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1517301 + ... + 1545147.

It is an arithmetic number, because the mean of its divisors is an integer number (796069890).

Almost surely, 2^42639994728 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 42639994728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63685591200).

42639994728 is an abundant number, since it is smaller than the sum of its proper divisors (84731187672).

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

42639994728 is a wasteful number, since it uses less digits than its factorization.

42639994728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28021 (or 28008 counting only the distinct ones).

The product of its digits is 47029248, while the sum is 63.

The spelling of 42639994728 in words is "forty-two billion, six hundred thirty-nine million, nine hundred ninety-four thousand, seven hundred twenty-eight".