67145221 has 24 divisors (see below), whose sum is σ = 83535840. Its totient is φ = 53352000.

The previous prime is 67145213. The next prime is 67145233. The reversal of 67145221 is 12254176.

It is not a de Polignac number, because 67145221 - 2³ = 67145213 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 67145221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67145821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34371 + ... + 36271.

It is an arithmetic number, because the mean of its divisors is an integer number (3480660).

Almost surely, 2^67145221 is an apocalyptic number.

It is an amenable number.

67145221 is a deficient number, since it is larger than the sum of its proper divisors (16390619).

67145221 is a wasteful number, since it uses less digits than its factorization.

67145221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1957 (or 1944 counting only the distinct ones).

The product of its digits is 3360, while the sum is 28.

The square root of 67145221 is about 8194.2187547075. The cubic root of 67145221 is about 406.4480421078.

Adding to 67145221 its reverse (12254176), we get a palindrome (79399397).

It can be divided in two parts, 6714 and 5221, that added together give a triangular number (11935 = T₁₅₄).

The spelling of 67145221 in words is "sixty-seven million, one hundred forty-five thousand, two hundred twenty-one".