67013521 has 4 divisors (see below), whose sum is σ = 67274532. Its totient is φ = 66752512.

The previous prime is 67013509. The next prime is 67013533. The reversal of 67013521 is 12531076.

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 (67013509) and next prime (67013533).

It can be written as a sum of positive squares in 2 ways, for example, as 63361600 + 3651921 = 7960^2 + 1911^2 .

It is a cyclic number.

It is not a de Polignac number, because 67013521 - 2¹¹ = 67011473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67013501) 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, 130120 + ... + 130633.

It is an arithmetic number, because the mean of its divisors is an integer number (16818633).

Almost surely, 2^67013521 is an apocalyptic number.

It is an amenable number.

67013521 is a deficient number, since it is larger than the sum of its proper divisors (261011).

67013521 is a wasteful number, since it uses less digits than its factorization.

67013521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261010.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 67013521 is about 8186.1786567360. The cubic root of 67013521 is about 406.1821296954.

Adding to 67013521 its reverse (12531076), we get a palindrome (79544597).

The spelling of 67013521 in words is "sixty-seven million, thirteen thousand, five hundred twenty-one".