8378729 has 4 divisors (see below), whose sum is σ = 8386560. Its totient is φ = 8370900.

The previous prime is 8378723. The next prime is 8378731. The reversal of 8378729 is 9278738.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 8378729 - 2²⁰ = 7330153 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 8378729.

It is not an unprimeable number, because it can be changed into a prime (8378723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1997 + ... + 4554.

It is an arithmetic number, because the mean of its divisors is an integer number (2096640).

Almost surely, 2^8378729 is an apocalyptic number.

It is an amenable number.

8378729 is a deficient number, since it is larger than the sum of its proper divisors (7831).

8378729 is a wasteful number, since it uses less digits than its factorization.

8378729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7830.

The product of its digits is 169344, while the sum is 44.

The square root of 8378729 is about 2894.6034270691. The cubic root of 8378729 is about 203.1075408741.

Subtracting 8378729 from its reverse (9278738), we obtain a palindrome (900009).

The spelling of 8378729 in words is "eight million, three hundred seventy-eight thousand, seven hundred twenty-nine".