749657921 has 2 divisors, whose sum is σ = 749657922. Its totient is φ = 749657920.

The previous prime is 749657893. The next prime is 749657941. The reversal of 749657921 is 129756947.

749657921 = 19360² + 19361².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 374848321 + 374809600 = 19361^2 + 19360^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-749657921 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 749657921.

It is not a weakly prime, because it can be changed into another prime (749657941) 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, 374828960 + 374828961.

It is an arithmetic number, because the mean of its divisors is an integer number (374828961).

Almost surely, 2^749657921 is an apocalyptic number.

749657921 is the 19361-st centered square number.

It is an amenable number.

749657921 is a deficient number, since it is larger than the sum of its proper divisors (1).

749657921 is an equidigital number, since it uses as much as digits as its factorization.

749657921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 952560, while the sum is 50.

The square root of 749657921 is about 27379.8816834551. The cubic root of 749657921 is about 908.4221423441.

The spelling of 749657921 in words is "seven hundred forty-nine million, six hundred fifty-seven thousand, nine hundred twenty-one".