681848221 has 2 divisors, whose sum is σ = 681848222. Its totient is φ = 681848220.

The previous prime is 681848107. The next prime is 681848239. The reversal of 681848221 is 122848186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 399440196 + 282408025 = 19986^2 + 16805^2 .

It is a cyclic number.

It is not a de Polignac number, because 681848221 - 2¹⁹ = 681323933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681848281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340924110 + 340924111.

It is an arithmetic number, because the mean of its divisors is an integer number (340924111).

Almost surely, 2^681848221 is an apocalyptic number.

It is an amenable number.

681848221 is a deficient number, since it is larger than the sum of its proper divisors (1).

681848221 is an equidigital number, since it uses as much as digits as its factorization.

681848221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 49152, while the sum is 40.

The square root of 681848221 is about 26112.2235935586. The cubic root of 681848221 is about 880.1619110656.

The spelling of 681848221 in words is "six hundred eighty-one million, eight hundred forty-eight thousand, two hundred twenty-one".