681240353 has 2 divisors, whose sum is σ = 681240354. Its totient is φ = 681240352.

The previous prime is 681240347. The next prime is 681240457. The reversal of 681240353 is 353042186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 659821969 + 21418384 = 25687^2 + 4628^2 .

It is a cyclic number.

It is not a de Polignac number, because 681240353 - 2¹⁰ = 681239329 is a prime.

It is not a weakly prime, because it can be changed into another prime (681248353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340620176 + 340620177.

It is an arithmetic number, because the mean of its divisors is an integer number (340620177).

Almost surely, 2^681240353 is an apocalyptic number.

It is an amenable number.

681240353 is a deficient number, since it is larger than the sum of its proper divisors (1).

681240353 is an equidigital number, since it uses as much as digits as its factorization.

681240353 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 681240353 is about 26100.5814686187. The cubic root of 681240353 is about 879.9002783866.

It can be divided in two parts, 68 and 1240353, that added together give a palindrome (1240421).

The spelling of 681240353 in words is "six hundred eighty-one million, two hundred forty thousand, three hundred fifty-three".