78212887 has 2 divisors, whose sum is σ = 78212888. Its totient is φ = 78212886.

The previous prime is 78212867. The next prime is 78212891. The reversal of 78212887 is 78821287.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78212887 - 2¹⁵ = 78180119 is a prime.

It is a super-2 number, since 2×78212887² = 12234511385749538, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78212867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39106443 + 39106444.

It is an arithmetic number, because the mean of its divisors is an integer number (39106444).

Almost surely, 2^78212887 is an apocalyptic number.

78212887 is a deficient number, since it is larger than the sum of its proper divisors (1).

78212887 is an equidigital number, since it uses as much as digits as its factorization.

78212887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 100352, while the sum is 43.

The square root of 78212887 is about 8843.8050068961. The cubic root of 78212887 is about 427.6542302284.

Subtracting 78212887 from its reverse (78821287), we obtain a square (608400 = 780²).

The spelling of 78212887 in words is "seventy-eight million, two hundred twelve thousand, eight hundred eighty-seven".