67106521 has 4 divisors (see below), whose sum is σ = 67771044. Its totient is φ = 66442000.

The previous prime is 67106503. The next prime is 67106539. The reversal of 67106521 is 12560176.

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

It is an interprime number because it is at equal distance from previous prime (67106503) and next prime (67106539).

It can be written as a sum of positive squares in 2 ways, for example, as 66194496 + 912025 = 8136^2 + 955^2 .

It is a cyclic number.

It is not a de Polignac number, because 67106521 - 2⁷ = 67106393 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 67106521.

It is not an unprimeable number, because it can be changed into a prime (67106561) 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, 332110 + ... + 332311.

It is an arithmetic number, because the mean of its divisors is an integer number (16942761).

Almost surely, 2^67106521 is an apocalyptic number.

It is an amenable number.

67106521 is a deficient number, since it is larger than the sum of its proper divisors (664523).

67106521 is a wasteful number, since it uses less digits than its factorization.

67106521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664522.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 67106521 is about 8191.8569933807. The cubic root of 67106521 is about 406.3699399389.

Adding to 67106521 its reverse (12560176), we get a palindrome (79666697).

It can be divided in two parts, 6710 and 6521, that added together give a palindrome (13231).

The spelling of 67106521 in words is "sixty-seven million, one hundred six thousand, five hundred twenty-one".