689823641 has 4 divisors (see below), whose sum is σ = 742887012. Its totient is φ = 636760272.

The previous prime is 689823581. The next prime is 689823643. The reversal of 689823641 is 146328986.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 146328986 = 2 ⋅73164493.

It can be written as a sum of positive squares in 2 ways, for example, as 222010000 + 467813641 = 14900^2 + 21629^2 .

It is a cyclic number.

It is not a de Polignac number, because 689823641 - 2²² = 685629337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (689823643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26531666 + ... + 26531691.

It is an arithmetic number, because the mean of its divisors is an integer number (185721753).

Almost surely, 2^689823641 is an apocalyptic number.

It is an amenable number.

689823641 is a deficient number, since it is larger than the sum of its proper divisors (53063371).

689823641 is a wasteful number, since it uses less digits than its factorization.

689823641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53063370.

The product of its digits is 497664, while the sum is 47.

The square root of 689823641 is about 26264.4939224041. The cubic root of 689823641 is about 883.5803005033.

The spelling of 689823641 in words is "six hundred eighty-nine million, eight hundred twenty-three thousand, six hundred forty-one".