689761 has 2 divisors, whose sum is σ = 689762. Its totient is φ = 689760.

The previous prime is 689723. The next prime is 689771. The reversal of 689761 is 167986.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 398161 + 291600 = 631^2 + 540^2 .

It is a cyclic number.

It is not a de Polignac number, because 689761 - 2¹⁵ = 656993 is a prime.

689761 is a lucky number.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 689761.

It is not a weakly prime, because it can be changed into another prime (689771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344880 + 344881.

It is an arithmetic number, because the mean of its divisors is an integer number (344881).

2⁶⁸⁹⁷⁶¹ is an apocalyptic number.

689761 is the 480-th hex number.

It is an amenable number.

689761 is a deficient number, since it is larger than the sum of its proper divisors (1).

689761 is an equidigital number, since it uses as much as digits as its factorization.

689761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 37.

The square root of 689761 is about 830.5185127377. The cubic root of 689761 is about 88.3553554523.

The spelling of 689761 in words is "six hundred eighty-nine thousand, seven hundred sixty-one".