78278887 has 2 divisors, whose sum is σ = 78278888. Its totient is φ = 78278886.

The previous prime is 78278869. The next prime is 78278891. The reversal of 78278887 is 78887287.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78278887 - 2¹¹ = 78276839 is a prime.

It is a super-2 number, since 2×78278887² = 12255168299917538, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78278857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39139443 + 39139444.

It is an arithmetic number, because the mean of its divisors is an integer number (39139444).

Almost surely, 2^78278887 is an apocalyptic number.

78278887 is a deficient number, since it is larger than the sum of its proper divisors (1).

78278887 is an equidigital number, since it uses as much as digits as its factorization.

78278887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2809856, while the sum is 55.

The square root of 78278887 is about 8847.5356455908. The cubic root of 78278887 is about 427.7744885163.

Subtracting 78278887 from its reverse (78887287), we obtain a square (608400 = 780²).

The spelling of 78278887 in words is "seventy-eight million, two hundred seventy-eight thousand, eight hundred eighty-seven".