689394457 has 4 divisors (see below), whose sum is σ = 689465700. Its totient is φ = 689323216.

The previous prime is 689394403. The next prime is 689394463. The reversal of 689394457 is 754493986.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 318408336 + 370986121 = 17844^2 + 19261^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689394457 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 689394398 and 689394407.

It is not an unprimeable number, because it can be changed into a prime (689394487) 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, 18298 + ... + 41395.

It is an arithmetic number, because the mean of its divisors is an integer number (172366425).

Almost surely, 2^689394457 is an apocalyptic number.

It is an amenable number.

689394457 is a deficient number, since it is larger than the sum of its proper divisors (71243).

689394457 is a wasteful number, since it uses less digits than its factorization.

689394457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71242.

The product of its digits is 6531840, while the sum is 55.

The square root of 689394457 is about 26256.3222291318. The cubic root of 689394457 is about 883.3970182952.

The spelling of 689394457 in words is "six hundred eighty-nine million, three hundred ninety-four thousand, four hundred fifty-seven".