689351697421 has 2 divisors, whose sum is σ = 689351697422. Its totient is φ = 689351697420.

The previous prime is 689351697407. The next prime is 689351697469. The reversal of 689351697421 is 124796153986.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 578519966025 + 110831731396 = 760605^2 + 332914^2 .

It is a cyclic number.

It is not a de Polignac number, because 689351697421 - 2²⁹ = 688814826509 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 689351697421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689351697521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344675848710 + 344675848711.

It is an arithmetic number, because the mean of its divisors is an integer number (344675848711).

Almost surely, 2^689351697421 is an apocalyptic number.

It is an amenable number.

689351697421 is a deficient number, since it is larger than the sum of its proper divisors (1).

689351697421 is an equidigital number, since it uses as much as digits as its factorization.

689351697421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19595520, while the sum is 61.

The spelling of 689351697421 in words is "six hundred eighty-nine billion, three hundred fifty-one million, six hundred ninety-seven thousand, four hundred twenty-one".