40007218 has 4 divisors (see below), whose sum is σ = 60010830. Its totient is φ = 20003608.

The previous prime is 40007207. The next prime is 40007221. The reversal of 40007218 is 81270004.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 28697449 + 11309769 = 5357^2 + 3363^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10001803 + ... + 10001806.

Almost surely, 2^40007218 is an apocalyptic number.

40007218 is a deficient number, since it is larger than the sum of its proper divisors (20003612).

40007218 is a wasteful number, since it uses less digits than its factorization.

40007218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20003611.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 40007218 is about 6325.1259276002. The cubic root of 40007218 is about 342.0157591088.

The spelling of 40007218 in words is "forty million, seven thousand, two hundred eighteen".