681495197 has 2 divisors, whose sum is σ = 681495198. Its totient is φ = 681495196.

The previous prime is 681495187. The next prime is 681495229. The reversal of 681495197 is 791594186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 551968036 + 129527161 = 23494^2 + 11381^2 .

It is a cyclic number.

It is not a de Polignac number, because 681495197 - 2⁴ = 681495181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681495137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340747598 + 340747599.

It is an arithmetic number, because the mean of its divisors is an integer number (340747599).

Almost surely, 2^681495197 is an apocalyptic number.

It is an amenable number.

681495197 is a deficient number, since it is larger than the sum of its proper divisors (1).

681495197 is an equidigital number, since it uses as much as digits as its factorization.

681495197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 50.

The square root of 681495197 is about 26105.4629723359. The cubic root of 681495197 is about 880.0099848213.

The spelling of 681495197 in words is "six hundred eighty-one million, four hundred ninety-five thousand, one hundred ninety-seven".