67351621 has 2 divisors, whose sum is σ = 67351622. Its totient is φ = 67351620.

The previous prime is 67351619. The next prime is 67351633. The reversal of 67351621 is 12615376.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43046721 + 24304900 = 6561^2 + 4930^2 .

It is a cyclic number.

It is not a de Polignac number, because 67351621 - 2¹ = 67351619 is a prime.

Together with 67351619, 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 (67351121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33675810 + 33675811.

It is an arithmetic number, because the mean of its divisors is an integer number (33675811).

Almost surely, 2^67351621 is an apocalyptic number.

It is an amenable number.

67351621 is a deficient number, since it is larger than the sum of its proper divisors (1).

67351621 is an equidigital number, since it uses as much as digits as its factorization.

67351621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 31.

The square root of 67351621 is about 8206.8033362571. The cubic root of 67351621 is about 406.8640809700.

Adding to 67351621 its reverse (12615376), we get a palindrome (79966997).

The spelling of 67351621 in words is "sixty-seven million, three hundred fifty-one thousand, six hundred twenty-one".