40218217 has 4 divisors (see below), whose sum is σ = 43311940. Its totient is φ = 37124496.

The previous prime is 40218181. The next prime is 40218247. The reversal of 40218217 is 71281204.

It is a happy number.

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 9126441 + 31091776 = 3021^2 + 5576^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40218217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40218191 and 40218200.

It is not an unprimeable number, because it can be changed into a prime (40218247) 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, 1546842 + ... + 1546867.

It is an arithmetic number, because the mean of its divisors is an integer number (10827985).

Almost surely, 2^40218217 is an apocalyptic number.

It is an amenable number.

40218217 is a deficient number, since it is larger than the sum of its proper divisors (3093723).

40218217 is a wasteful number, since it uses less digits than its factorization.

40218217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3093722.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 40218217 is about 6341.7834242427. The cubic root of 40218217 is about 342.6159715252.

The spelling of 40218217 in words is "forty million, two hundred eighteen thousand, two hundred seventeen".