681864273 has 6 divisors (see below), whose sum is σ = 984915074. Its totient is φ = 454576176.

The previous prime is 681864257. The next prime is 681864319. The reversal of 681864273 is 372468186.

It can be written as a sum of positive squares in only one way, i.e., 382124304 + 299739969 = 19548^2 + 17313^2 .

It is not a de Polignac number, because 681864273 - 2⁴ = 681864257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681864473) 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, 37881340 + ... + 37881357.

Almost surely, 2^681864273 is an apocalyptic number.

It is an amenable number.

681864273 is a deficient number, since it is larger than the sum of its proper divisors (303050801).

681864273 is a wasteful number, since it uses less digits than its factorization.

681864273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75762703 (or 75762700 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 681864273 is about 26112.5309573775. The cubic root of 681864273 is about 880.1688179049.

The spelling of 681864273 in words is "six hundred eighty-one million, eight hundred sixty-four thousand, two hundred seventy-three".