67878491 has 2 divisors, whose sum is σ = 67878492. Its totient is φ = 67878490.

The previous prime is 67878487. The next prime is 67878509. The reversal of 67878491 is 19487876.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 67878491 - 2² = 67878487 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (67878191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33939245 + 33939246.

It is an arithmetic number, because the mean of its divisors is an integer number (33939246).

Almost surely, 2^67878491 is an apocalyptic number.

67878491 is a deficient number, since it is larger than the sum of its proper divisors (1).

67878491 is an equidigital number, since it uses as much as digits as its factorization.

67878491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 677376, while the sum is 50.

The square root of 67878491 is about 8238.8403917056. The cubic root of 67878491 is about 407.9222486565.

The spelling of 67878491 in words is "sixty-seven million, eight hundred seventy-eight thousand, four hundred ninety-one".