78388387 has 12 divisors (see below), whose sum is σ = 99476856. Its totient is φ = 61081440.

The previous prime is 78388381. The next prime is 78388397.

78388387 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 78388387 - 2³ = 78388379 is a prime.

It is a super-2 number, since 2×78388387² = 12289478432923538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78388381) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72178 + ... + 73255.

It is an arithmetic number, because the mean of its divisors is an integer number (8289738).

Almost surely, 2^78388387 is an apocalyptic number.

78388387 is a gapful number since it is divisible by the number (77) formed by its first and last digit.

78388387 is a deficient number, since it is larger than the sum of its proper divisors (21088469).

78388387 is a wasteful number, since it uses less digits than its factorization.

78388387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145458 (or 145451 counting only the distinct ones).

The product of its digits is 1806336, while the sum is 52.

The square root of 78388387 is about 8853.7216468556. The cubic root of 78388387 is about 427.9738589298.

The spelling of 78388387 in words is "seventy-eight million, three hundred eighty-eight thousand, three hundred eighty-seven".