684173969 has 2 divisors, whose sum is σ = 684173970. Its totient is φ = 684173968.

The previous prime is 684173957. The next prime is 684174013. The reversal of 684173969 is 969371486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 652138369 + 32035600 = 25537^2 + 5660^2 .

It is a cyclic number.

It is not a de Polignac number, because 684173969 - 2⁴ = 684173953 is a prime.

It is a super-2 number, since 2×684173969² = 936188039714425922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 684173969.

It is not a weakly prime, because it can be changed into another prime (684173909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342086984 + 342086985.

It is an arithmetic number, because the mean of its divisors is an integer number (342086985).

Almost surely, 2^684173969 is an apocalyptic number.

It is an amenable number.

684173969 is a deficient number, since it is larger than the sum of its proper divisors (1).

684173969 is an equidigital number, since it uses as much as digits as its factorization.

684173969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1959552, while the sum is 53.

The square root of 684173969 is about 26156.7193852746. The cubic root of 684173969 is about 881.1615038878.

The spelling of 684173969 in words is "six hundred eighty-four million, one hundred seventy-three thousand, nine hundred sixty-nine".