684284978 has 8 divisors (see below), whose sum is σ = 1105383468. Its totient is φ = 315823824.

The previous prime is 684284933. The next prime is 684284987. The reversal of 684284978 is 879482486.

It can be written as a sum of positive squares in 2 ways, for example, as 683665609 + 619369 = 26147^2 + 787^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×684284978² = 936491862232920968, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13159301 + ... + 13159352.

Almost surely, 2^684284978 is an apocalyptic number.

684284978 is a deficient number, since it is larger than the sum of its proper divisors (421098490).

684284978 is a wasteful number, since it uses less digits than its factorization.

684284978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26318668.

The product of its digits is 6193152, while the sum is 56.

The square root of 684284978 is about 26158.8412969688. The cubic root of 684284978 is about 881.2091582232.

The spelling of 684284978 in words is "six hundred eighty-four million, two hundred eighty-four thousand, nine hundred seventy-eight".