681899 has 2 divisors, whose sum is σ = 681900. Its totient is φ = 681898.

The previous prime is 681883. The next prime is 681913. The reversal of 681899 is 998186.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 681899 - 2⁴ = 681883 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (681809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340949 + 340950.

It is an arithmetic number, because the mean of its divisors is an integer number (340950).

2⁶⁸¹⁸⁹⁹ is an apocalyptic number.

681899 is a deficient number, since it is larger than the sum of its proper divisors (1).

681899 is an equidigital number, since it uses as much as digits as its factorization.

681899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 41.

The square root of 681899 is about 825.7717602340. The cubic root of 681899 is about 88.0183759834.

The spelling of 681899 in words is "six hundred eighty-one thousand, eight hundred ninety-nine".