67644013 has 2 divisors, whose sum is σ = 67644014. Its totient is φ = 67644012.

The previous prime is 67644011. The next prime is 67644041. The reversal of 67644013 is 31044676.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59876644 + 7767369 = 7738^2 + 2787^2 .

It is a cyclic number.

It is not a de Polignac number, because 67644013 - 2¹ = 67644011 is a prime.

Together with 67644011, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67644011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33822006 + 33822007.

It is an arithmetic number, because the mean of its divisors is an integer number (33822007).

Almost surely, 2^67644013 is an apocalyptic number.

It is an amenable number.

67644013 is a deficient number, since it is larger than the sum of its proper divisors (1).

67644013 is an equidigital number, since it uses as much as digits as its factorization.

67644013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 31.

The square root of 67644013 is about 8224.5980448895. The cubic root of 67644013 is about 407.4520008201.

Adding to 67644013 its reverse (31044676), we get a palindrome (98688689).

The spelling of 67644013 in words is "sixty-seven million, six hundred forty-four thousand, thirteen".