42991728 has 40 divisors (see below), whose sum is σ = 119606928. Its totient is φ = 13228032.

The previous prime is 42991681. The next prime is 42991733. The reversal of 42991728 is 82719924.

It is a self number, because there is not a number n which added to its sum of digits gives 42991728.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33825 + ... + 35072.

Almost surely, 2^42991728 is an apocalyptic number.

42991728 is a gapful number since it is divisible by the number (48) formed by its first and last digit.

It is an amenable number.

42991728 is an abundant number, since it is smaller than the sum of its proper divisors (76615200).

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

42991728 is a wasteful number, since it uses less digits than its factorization.

42991728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68921 (or 68915 counting only the distinct ones).

The product of its digits is 72576, while the sum is 42.

The square root of 42991728 is about 6556.8077598783. The cubic root of 42991728 is about 350.3173393974.

The spelling of 42991728 in words is "forty-two million, nine hundred ninety-one thousand, seven hundred twenty-eight".