67994721 has 10 divisors (see below), whose sum is σ = 101572482. Its totient is φ = 45329760.

The previous prime is 67994701. The next prime is 67994723. The reversal of 67994721 is 12749976.

It can be written as a sum of positive squares in only one way, i.e., 64883025 + 3111696 = 8055^2 + 1764^2 .

It is not a de Polignac number, because 67994721 - 2⁷ = 67994593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (67994723) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 419640 + ... + 419801.

Almost surely, 2^67994721 is an apocalyptic number.

It is an amenable number.

67994721 is a deficient number, since it is larger than the sum of its proper divisors (33577761).

67994721 is an equidigital number, since it uses as much as digits as its factorization.

67994721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 839453 (or 839444 counting only the distinct ones).

The product of its digits is 190512, while the sum is 45.

The square root of 67994721 is about 8245.8911586317. The cubic root of 67994721 is about 408.1549476354.

The spelling of 67994721 in words is "sixty-seven million, nine hundred ninety-four thousand, seven hundred twenty-one".