685800001 has 2 divisors, whose sum is σ = 685800002. Its totient is φ = 685800000.

The previous prime is 685799957. The next prime is 685800013. The reversal of 685800001 is 100008586.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 401000625 + 284799376 = 20025^2 + 16876^2 .

It is a cyclic number.

It is not a de Polignac number, because 685800001 - 2²⁹ = 148929089 is a prime.

It is not a weakly prime, because it can be changed into another prime (685800061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342900000 + 342900001.

It is an arithmetic number, because the mean of its divisors is an integer number (342900001).

Almost surely, 2^685800001 is an apocalyptic number.

It is an amenable number.

685800001 is a deficient number, since it is larger than the sum of its proper divisors (1).

685800001 is an equidigital number, since it uses as much as digits as its factorization.

685800001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 685800001 is about 26187.7834304471. The cubic root of 685800001 is about 881.8590181094.

Adding to 685800001 its reverse (100008586), we get a palindrome (785808587).

The spelling of 685800001 in words is "six hundred eighty-five million, eight hundred thousand, one".