42643217 has 4 divisors (see below), whose sum is σ = 43447860. Its totient is φ = 41838576.

The previous prime is 42643213. The next prime is 42643247. The reversal of 42643217 is 71234624.

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 31460881 + 11182336 = 5609^2 + 3344^2 .

It is a cyclic number.

It is not a de Polignac number, because 42643217 - 2² = 42643213 is a prime.

It is a super-2 number, since 2×42643217² = 3636887912218178, which contains 22 as substring.

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 42643217.

It is not an unprimeable number, because it can be changed into a prime (42643213) 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, 402242 + ... + 402347.

It is an arithmetic number, because the mean of its divisors is an integer number (10861965).

Almost surely, 2^42643217 is an apocalyptic number.

It is an amenable number.

42643217 is a deficient number, since it is larger than the sum of its proper divisors (804643).

42643217 is an equidigital number, since it uses as much as digits as its factorization.

42643217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804642.

The product of its digits is 8064, while the sum is 29.

The square root of 42643217 is about 6530.1774095349. The cubic root of 42643217 is about 349.3681580047.

The spelling of 42643217 in words is "forty-two million, six hundred forty-three thousand, two hundred seventeen".