681001217 has 6 divisors (see below), whose sum is σ = 737415702. Its totient is φ = 628616352.

The previous prime is 681001213. The next prime is 681001219. The reversal of 681001217 is 712100186.

It is a Cunningham number, because it is equal to 26096²+1.

It can be written as a sum of positive squares in 3 ways, for example, as 1 + 681001216 = 1^2 + 26096^2 .

It is not a de Polignac number, because 681001217 - 2² = 681001213 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681001213) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2014628 + ... + 2014965.

It is an arithmetic number, because the mean of its divisors is an integer number (122902617).

Almost surely, 2^681001217 is an apocalyptic number.

It is an amenable number.

681001217 is a deficient number, since it is larger than the sum of its proper divisors (56414485).

681001217 is a wasteful number, since it uses less digits than its factorization.

681001217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4029619 (or 4029606 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 26.

The square root of 681001217 is about 26096.0000191600. Note that the first 4 decimals coincide. The cubic root of 681001217 is about 879.7973091200.

The spelling of 681001217 in words is "six hundred eighty-one million, one thousand, two hundred seventeen".