42721686 has 48 divisors (see below), whose sum is σ = 106173600. Its totient is φ = 12161664.

The previous prime is 42721681. The next prime is 42721711. The reversal of 42721686 is 68612724.

42721686 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 42721686.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42721681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51120 + ... + 51948.

It is an arithmetic number, because the mean of its divisors is an integer number (2211950).

Almost surely, 2^42721686 is an apocalyptic number.

42721686 is an abundant number, since it is smaller than the sum of its proper divisors (63451914).

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

42721686 is a wasteful number, since it uses less digits than its factorization.

42721686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1253 (or 1250 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 42721686 is about 6536.1828309802. The cubic root of 42721686 is about 349.5823208004.

The spelling of 42721686 in words is "forty-two million, seven hundred twenty-one thousand, six hundred eighty-six".