67218145 has 4 divisors (see below), whose sum is σ = 80661780. Its totient is φ = 53774512.

The previous prime is 67218139. The next prime is 67218161. The reversal of 67218145 is 54181276.

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 42497361 + 24720784 = 6519^2 + 4972^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67218145 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 67218145.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6721810 + ... + 6721819.

It is an arithmetic number, because the mean of its divisors is an integer number (20165445).

Almost surely, 2^67218145 is an apocalyptic number.

It is an amenable number.

67218145 is a deficient number, since it is larger than the sum of its proper divisors (13443635).

67218145 is a wasteful number, since it uses less digits than its factorization.

67218145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13443634.

The product of its digits is 13440, while the sum is 34.

The square root of 67218145 is about 8198.6672697457. The cubic root of 67218145 is about 406.5951317185.

The spelling of 67218145 in words is "sixty-seven million, two hundred eighteen thousand, one hundred forty-five".