67988321 has 4 divisors (see below), whose sum is σ = 71987652. Its totient is φ = 63988992.

The previous prime is 67988293. The next prime is 67988339. The reversal of 67988321 is 12388976.

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

It can be written as a sum of positive squares in 2 ways, for example, as 37957921 + 30030400 = 6161^2 + 5480^2 .

It is a cyclic number.

It is not a de Polignac number, because 67988321 - 2¹⁸ = 67726177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67988521) 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, 1999640 + ... + 1999673.

It is an arithmetic number, because the mean of its divisors is an integer number (17996913).

Almost surely, 2^67988321 is an apocalyptic number.

It is an amenable number.

67988321 is a deficient number, since it is larger than the sum of its proper divisors (3999331).

67988321 is a wasteful number, since it uses less digits than its factorization.

67988321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3999330.

The product of its digits is 145152, while the sum is 44.

The square root of 67988321 is about 8245.5030774356. The cubic root of 67988321 is about 408.1421413784.

The spelling of 67988321 in words is "sixty-seven million, nine hundred eighty-eight thousand, three hundred twenty-one".