765145921 has 2 divisors, whose sum is σ = 765145922. Its totient is φ = 765145920.

The previous prime is 765145907. The next prime is 765145967. The reversal of 765145921 is 129541567.

765145921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 747202225 + 17943696 = 27335^2 + 4236^2 .

It is an emirp because it is prime and its reverse (129541567) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 765145921 - 2⁷ = 765145793 is a prime.

It is equal to p_39443584 and since 765145921 and 39443584 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (765145621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 382572960 + 382572961.

It is an arithmetic number, because the mean of its divisors is an integer number (382572961).

Almost surely, 2^765145921 is an apocalyptic number.

It is an amenable number.

765145921 is a deficient number, since it is larger than the sum of its proper divisors (1).

765145921 is an equidigital number, since it uses as much as digits as its factorization.

765145921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 75600, while the sum is 40.

The square root of 765145921 is about 27661.2711385431. The cubic root of 765145921 is about 914.6355744656.

The spelling of 765145921 in words is "seven hundred sixty-five million, one hundred forty-five thousand, nine hundred twenty-one".