684814681 has 2 divisors, whose sum is σ = 684814682. Its totient is φ = 684814680.

The previous prime is 684814633. The next prime is 684814693. The reversal of 684814681 is 186418486.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 650709081 + 34105600 = 25509^2 + 5840^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-684814681 is a prime.

It is a super-2 number, since 2×684814681² = 937942294626263522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (684814601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342407340 + 342407341.

It is an arithmetic number, because the mean of its divisors is an integer number (342407341).

Almost surely, 2^684814681 is an apocalyptic number.

It is an amenable number.

684814681 is a deficient number, since it is larger than the sum of its proper divisors (1).

684814681 is an equidigital number, since it uses as much as digits as its factorization.

684814681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 294912, while the sum is 46.

The square root of 684814681 is about 26168.9640796116. The cubic root of 684814681 is about 881.4364800542.

The spelling of 684814681 in words is "six hundred eighty-four million, eight hundred fourteen thousand, six hundred eighty-one".