764243681 has 2 divisors, whose sum is σ = 764243682. Its totient is φ = 764243680.

The previous prime is 764243657. The next prime is 764243719. The reversal of 764243681 is 186342467.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 762643456 + 1600225 = 27616^2 + 1265^2 .

It is an emirp because it is prime and its reverse (186342467) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 764243681 - 2⁶ = 764243617 is a prime.

It is a super-2 number, since 2×764243681² = 1168136807896859522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (764243611) 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, 382121840 + 382121841.

It is an arithmetic number, because the mean of its divisors is an integer number (382121841).

Almost surely, 2^764243681 is an apocalyptic number.

It is an amenable number.

764243681 is a deficient number, since it is larger than the sum of its proper divisors (1).

764243681 is an equidigital number, since it uses as much as digits as its factorization.

764243681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 41.

The square root of 764243681 is about 27644.9576053211. The cubic root of 764243681 is about 914.2759283074.

The spelling of 764243681 in words is "seven hundred sixty-four million, two hundred forty-three thousand, six hundred eighty-one".