764665204421 has 2 divisors, whose sum is σ = 764665204422. Its totient is φ = 764665204420.

The previous prime is 764665204403. The next prime is 764665204423. The reversal of 764665204421 is 124402566467.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 705114563521 + 59550640900 = 839711^2 + 244030^2 .

It is an emirp because it is prime and its reverse (124402566467) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 764665204421 - 2¹⁰ = 764665203397 is a prime.

Together with 764665204423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (764665204423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 382332602210 + 382332602211.

It is an arithmetic number, because the mean of its divisors is an integer number (382332602211).

Almost surely, 2^764665204421 is an apocalyptic number.

It is an amenable number.

764665204421 is a deficient number, since it is larger than the sum of its proper divisors (1).

764665204421 is an equidigital number, since it uses as much as digits as its factorization.

764665204421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1935360, while the sum is 47.

The spelling of 764665204421 in words is "seven hundred sixty-four billion, six hundred sixty-five million, two hundred four thousand, four hundred twenty-one".