755687921 has 2 divisors, whose sum is σ = 755687922. Its totient is φ = 755687920.

The previous prime is 755687879. The next prime is 755687923. The reversal of 755687921 is 129786557.

755687921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 390457600 + 365230321 = 19760^2 + 19111^2 .

It is an emirp because it is prime and its reverse (129786557) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 755687921 - 2⁶ = 755687857 is a prime.

Together with 755687923, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 755687921.

It is not a weakly prime, because it can be changed into another prime (755687923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 377843960 + 377843961.

It is an arithmetic number, because the mean of its divisors is an integer number (377843961).

Almost surely, 2^755687921 is an apocalyptic number.

It is an amenable number.

755687921 is a deficient number, since it is larger than the sum of its proper divisors (1).

755687921 is an equidigital number, since it uses as much as digits as its factorization.

755687921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1058400, while the sum is 50.

The square root of 755687921 is about 27489.7784821922. The cubic root of 755687921 is about 910.8513230339.

The spelling of 755687921 in words is "seven hundred fifty-five million, six hundred eighty-seven thousand, nine hundred twenty-one".