684239747 has 4 divisors (see below), whose sum is σ = 690295080. Its totient is φ = 678184416.

The previous prime is 684239741. The next prime is 684239767. The reversal of 684239747 is 747932486.

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

It is a de Polignac number, because none of the positive numbers 2^k-684239747 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 684239695 and 684239704.

It is not an unprimeable number, because it can be changed into a prime (684239741) by changing a digit.

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, 3027497 + ... + 3027722.

It is an arithmetic number, because the mean of its divisors is an integer number (172573770).

Almost surely, 2^684239747 is an apocalyptic number.

684239747 is a deficient number, since it is larger than the sum of its proper divisors (6055333).

684239747 is a wasteful number, since it uses less digits than its factorization.

684239747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6055332.

The product of its digits is 2032128, while the sum is 50.

The square root of 684239747 is about 26157.9767375078. The cubic root of 684239747 is about 881.1897419221.

The spelling of 684239747 in words is "six hundred eighty-four million, two hundred thirty-nine thousand, seven hundred forty-seven".