67561321 has 4 divisors (see below), whose sum is σ = 71117200. Its totient is φ = 64005444.

The previous prime is 67561309. The next prime is 67561331. The reversal of 67561321 is 12316576.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 67561321 - 2⁹ = 67560809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67561301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1777911 + ... + 1777948.

It is an arithmetic number, because the mean of its divisors is an integer number (17779300).

Almost surely, 2^67561321 is an apocalyptic number.

It is an amenable number.

67561321 is a deficient number, since it is larger than the sum of its proper divisors (3555879).

67561321 is a wasteful number, since it uses less digits than its factorization.

67561321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3555878.

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

The square root of 67561321 is about 8219.5693926142. The cubic root of 67561321 is about 407.2859020622.

Adding to 67561321 its reverse (12316576), we get a palindrome (79877897).

The spelling of 67561321 in words is "sixty-seven million, five hundred sixty-one thousand, three hundred twenty-one".