67921921 has 8 divisors (see below), whose sum is σ = 72077760. Its totient is φ = 63866352.

The previous prime is 67921883. The next prime is 67921943. The reversal of 67921921 is 12912976.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 67921921 - 2¹⁹ = 67397633 is a prime.

It is a super-2 number, since 2×67921921² = 9226774704660482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67921951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23670 + ... + 26383.

It is an arithmetic number, because the mean of its divisors is an integer number (9009720).

Almost surely, 2^67921921 is an apocalyptic number.

It is an amenable number.

67921921 is a deficient number, since it is larger than the sum of its proper divisors (4155839).

67921921 is a wasteful number, since it uses less digits than its factorization.

67921921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50135.

The product of its digits is 13608, while the sum is 37.

The square root of 67921921 is about 8241.4756567013. The cubic root of 67921921 is about 408.0092290140.

The spelling of 67921921 in words is "sixty-seven million, nine hundred twenty-one thousand, nine hundred twenty-one".