684426731 has 4 divisors (see below), whose sum is σ = 688625832. Its totient is φ = 680227632.

The previous prime is 684426713. The next prime is 684426739. The reversal of 684426731 is 137624486.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-684426731 is a prime.

It is a super-2 number, since 2×684426731² = 936879900214692722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (684426739) 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, 2099306 + ... + 2099631.

It is an arithmetic number, because the mean of its divisors is an integer number (172156458).

Almost surely, 2^684426731 is an apocalyptic number.

684426731 is a deficient number, since it is larger than the sum of its proper divisors (4199101).

684426731 is a wasteful number, since it uses less digits than its factorization.

684426731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4199100.

The product of its digits is 193536, while the sum is 41.

The square root of 684426731 is about 26161.5506230040. The cubic root of 684426731 is about 881.2700029596.

The spelling of 684426731 in words is "six hundred eighty-four million, four hundred twenty-six thousand, seven hundred thirty-one".