42215771 has 4 divisors (see below), whose sum is σ = 45463152.
Its totient is φ = 38968392.
The previous prime is 42215759. The next prime is 42215791. The reversal of 42215771 is 17751224.
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-42215771 is a prime.
It is a super-2 number, since 2×422157712 = 3564342642248882, which contains 22 as substring.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (42215731) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1623671 + ... + 1623696.
It is an arithmetic number, because the mean of its divisors is an integer number (11365788).
Almost surely, 242215771 is an apocalyptic number.
42215771 is a deficient number, since it is larger than the sum of its proper divisors (3247381).
42215771 is a wasteful number, since it uses less digits than its factorization.
42215771 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 3247380.
The product of its digits is 3920, while the sum is 29.
The square root of 42215771 is about 6497.3664665001.
The cubic root of 42215771 is about 348.1969065547.
Adding to 42215771 its reverse (17751224), we get a palindrome (59966995).
The spelling of 42215771 in words is "forty-two million, two hundred fifteen thousand, seven hundred seventy-one".