67777921 has 4 divisors (see below), whose sum is σ = 71345200. Its totient is φ = 64210644.

The previous prime is 67777907. The next prime is 67777979. The reversal of 67777921 is 12977776.

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 67777921 - 2⁵ = 67777889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67777981) 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, 1783611 + ... + 1783648.

It is an arithmetic number, because the mean of its divisors is an integer number (17836300).

Almost surely, 2^67777921 is an apocalyptic number.

It is an amenable number.

67777921 is a deficient number, since it is larger than the sum of its proper divisors (3567279).

67777921 is a wasteful number, since it uses less digits than its factorization.

67777921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3567278.

The product of its digits is 259308, while the sum is 46.

The square root of 67777921 is about 8232.7347218285. The cubic root of 67777921 is about 407.7206874175.

The spelling of 67777921 in words is "sixty-seven million, seven hundred seventy-seven thousand, nine hundred twenty-one".