78387289 has 16 divisors (see below), whose sum is σ = 86994432. Its totient is φ = 70253568.

The previous prime is 78387277. The next prime is 78387301. The reversal of 78387289 is 98278387.

It is an interprime number because it is at equal distance from previous prime (78387277) and next prime (78387301).

It is a cyclic number.

It is not a de Polignac number, because 78387289 - 2⁷ = 78387161 is a prime.

It is a super-2 number, since 2×78387289² = 12289134153539042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78387209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 169072 + ... + 169534.

It is an arithmetic number, because the mean of its divisors is an integer number (5437152).

Almost surely, 2^78387289 is an apocalyptic number.

It is an amenable number.

78387289 is a deficient number, since it is larger than the sum of its proper divisors (8607143).

78387289 is a wasteful number, since it uses less digits than its factorization.

78387289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936.

The product of its digits is 1354752, while the sum is 52.

The square root of 78387289 is about 8853.6596388160. The cubic root of 78387289 is about 427.9718606853.

The spelling of 78387289 in words is "seventy-eight million, three hundred eighty-seven thousand, two hundred eighty-nine".