684742726 has 4 divisors (see below), whose sum is σ = 1027114092. Its totient is φ = 342371362.

The previous prime is 684742717. The next prime is 684742733. The reversal of 684742726 is 627247486.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 627247486 = 2 ⋅313623743.

It is a super-2 number, since 2×684742726² = 937745201619822152, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 171185680 + ... + 171185683.

It is an arithmetic number, because the mean of its divisors is an integer number (256778523).

Almost surely, 2^684742726 is an apocalyptic number.

684742726 is a deficient number, since it is larger than the sum of its proper divisors (342371366).

684742726 is a wasteful number, since it uses less digits than its factorization.

684742726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342371365.

The product of its digits is 903168, while the sum is 46.

The square root of 684742726 is about 26167.5892278979. The cubic root of 684742726 is about 881.4056074765.

The spelling of 684742726 in words is "six hundred eighty-four million, seven hundred forty-two thousand, seven hundred twenty-six".