78436 has 6 divisors (see below), whose sum is σ = 137270. Its totient is φ = 39216.

The previous prime is 78427. The next prime is 78437. The reversal of 78436 is 63487.

It can be written as a sum of positive squares in only one way, i.e., 78400 + 36 = 280^2 + 6^2 .

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (78437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9801 + ... + 9808.

2⁷⁸⁴³⁶ is an apocalyptic number.

It is an amenable number.

78436 is a deficient number, since it is larger than the sum of its proper divisors (58834).

78436 is a wasteful number, since it uses less digits than its factorization.

78436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19613 (or 19611 counting only the distinct ones).

The product of its digits is 4032, while the sum is 28.

The square root of 78436 is about 280.0642783362. The cubic root of 78436 is about 42.8060491639.

It can be divided in two parts, 784 and 36, that multiplied together give a square (28224 = 168²).

The spelling of 78436 in words is "seventy-eight thousand, four hundred thirty-six".