42705621 has 24 divisors (see below), whose sum is σ = 70671744. Its totient is φ = 24343200.

The previous prime is 42705617. The next prime is 42705623. The reversal of 42705621 is 12650724.

42705621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 42705621 - 2² = 42705617 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42705623) 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, 43680 + ... + 44646.

It is an arithmetic number, because the mean of its divisors is an integer number (2944656).

Almost surely, 2^42705621 is an apocalyptic number.

It is an amenable number.

42705621 is a deficient number, since it is larger than the sum of its proper divisors (27966123).

42705621 is a wasteful number, since it uses less digits than its factorization.

42705621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1681 (or 1678 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 42705621 is about 6534.9537871358. The cubic root of 42705621 is about 349.5384964994.

The spelling of 42705621 in words is "forty-two million, seven hundred five thousand, six hundred twenty-one".