42807421 has 4 divisors (see below), whose sum is σ = 43509244. Its totient is φ = 42105600.

The previous prime is 42807397. The next prime is 42807473. The reversal of 42807421 is 12470824.

42807421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6446521 + 36360900 = 2539^2 + 6030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42807421 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42807421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42807481) 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 3 ways as a sum of consecutive naturals, for example, 350820 + ... + 350941.

It is an arithmetic number, because the mean of its divisors is an integer number (10877311).

Almost surely, 2^42807421 is an apocalyptic number.

It is an amenable number.

42807421 is a deficient number, since it is larger than the sum of its proper divisors (701823).

42807421 is an equidigital number, since it uses as much as digits as its factorization.

42807421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701822.

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 42807421 is about 6542.7380354099. The cubic root of 42807421 is about 349.8160148658.

The spelling of 42807421 in words is "forty-two million, eight hundred seven thousand, four hundred twenty-one".