681671293 has 2 divisors, whose sum is σ = 681671294. Its totient is φ = 681671292.

The previous prime is 681671261. The next prime is 681671297. The reversal of 681671293 is 392176186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 636149284 + 45522009 = 25222^2 + 6747^2 .

It is a cyclic number.

It is not a de Polignac number, because 681671293 - 2⁵ = 681671261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681671297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340835646 + 340835647.

It is an arithmetic number, because the mean of its divisors is an integer number (340835647).

Almost surely, 2^681671293 is an apocalyptic number.

It is an amenable number.

681671293 is a deficient number, since it is larger than the sum of its proper divisors (1).

681671293 is an equidigital number, since it uses as much as digits as its factorization.

681671293 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 43.

The square root of 681671293 is about 26108.8355351211. The cubic root of 681671293 is about 880.0857754717.

The spelling of 681671293 in words is "six hundred eighty-one million, six hundred seventy-one thousand, two hundred ninety-three".