78278287 has 2 divisors, whose sum is σ = 78278288. Its totient is φ = 78278286.

The previous prime is 78278237. The next prime is 78278293. The reversal of 78278287 is 78287287.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78278287 is a prime.

It is a super-2 number, since 2×78278287² = 12254980431308738, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78278287.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78278237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39139143 + 39139144.

It is an arithmetic number, because the mean of its divisors is an integer number (39139144).

Almost surely, 2^78278287 is an apocalyptic number.

78278287 is a deficient number, since it is larger than the sum of its proper divisors (1).

78278287 is an equidigital number, since it uses as much as digits as its factorization.

78278287 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 702464, while the sum is 49.

The square root of 78278287 is about 8847.5017377789. The cubic root of 78278287 is about 427.7733955636.

The spelling of 78278287 in words is "seventy-eight million, two hundred seventy-eight thousand, two hundred eighty-seven".