67278991 has 8 divisors (see below), whose sum is σ = 74222064. Its totient is φ = 60588480.

The previous prime is 67278977. The next prime is 67279001. The reversal of 67278991 is 19987276.

It is a happy number.

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 67278991 - 2¹¹ = 67276943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67278901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62581 + ... + 63646.

It is an arithmetic number, because the mean of its divisors is an integer number (9277758).

Almost surely, 2^67278991 is an apocalyptic number.

67278991 is a deficient number, since it is larger than the sum of its proper divisors (6943073).

67278991 is a wasteful number, since it uses less digits than its factorization.

67278991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126281.

The product of its digits is 381024, while the sum is 49.

The square root of 67278991 is about 8202.3771554349. The cubic root of 67278991 is about 406.7177782962.

The spelling of 67278991 in words is "sixty-seven million, two hundred seventy-eight thousand, nine hundred ninety-one".