42424721 has 4 divisors (see below), whose sum is σ = 42440244. Its totient is φ = 42409200.

The previous prime is 42424699. The next prime is 42424727. The reversal of 42424721 is 12742424.

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 31764496 + 10660225 = 5636^2 + 3265^2 .

It is a cyclic number.

It is not a de Polignac number, because 42424721 - 2¹⁰ = 42423697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42424727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2450 + ... + 9531.

It is an arithmetic number, because the mean of its divisors is an integer number (10610061).

Almost surely, 2^42424721 is an apocalyptic number.

It is an amenable number.

42424721 is a deficient number, since it is larger than the sum of its proper divisors (15523).

42424721 is a wasteful number, since it uses less digits than its factorization.

42424721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15522.

The product of its digits is 3584, while the sum is 26.

The square root of 42424721 is about 6513.4262105285. The cubic root of 42424721 is about 348.7704365751.

The spelling of 42424721 in words is "forty-two million, four hundred twenty-four thousand, seven hundred twenty-one".