40280065 has 32 divisors (see below), whose sum is σ = 56989440.
Its totient is φ = 26763264.
The previous prime is 40280063. The next prime is 40280083. The reversal of 40280065 is 56008204.
Adding to 40280065 its reverse (56008204), we get a palindrome (96288269).
It is a 3-Lehmer number, since φ(40280065) divides (40280065-1)3.
It is a cyclic number.
It is a Carmichael number.
It is not a de Polignac number, because 40280065 - 21 = 40280063 is a prime.
It is not an unprimeable number, because it can be changed into a prime (40280063) by changing a digit.
It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 208609 + ... + 208801.
It is an arithmetic number, because the mean of its divisors is an integer number (1780920).
It is a Proth number, since it is equal to 4917 ⋅ 213 + 1 and 4917 < 213.
It is a Poulet number, since it divides 240280064-1.
Almost surely, 240280065 is an apocalyptic number.
It is an amenable number.
40280065 is a deficient number, since it is larger than the sum of its proper divisors (16709375).
40280065 is a wasteful number, since it uses less digits than its factorization.
40280065 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 361.
The product of its (nonzero) digits is 1920, while the sum is 25.
The square root of 40280065 is about 6346.6577818565.
The cubic root of 40280065 is about 342.7915077319.
The spelling of 40280065 in words is "forty million, two hundred eighty thousand, sixty-five".