773145721 has 2 divisors, whose sum is σ = 773145722. Its totient is φ = 773145720.

The previous prime is 773145697. The next prime is 773145731. The reversal of 773145721 is 127541377.

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., 772562025 + 583696 = 27795^2 + 764^2 .

It is an emirp because it is prime and its reverse (127541377) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 773145721 - 2¹¹ = 773143673 is a prime.

It is not a weakly prime, because it can be changed into another prime (773145731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 386572860 + 386572861.

It is an arithmetic number, because the mean of its divisors is an integer number (386572861).

Almost surely, 2^773145721 is an apocalyptic number.

It is an amenable number.

773145721 is a deficient number, since it is larger than the sum of its proper divisors (1).

773145721 is an equidigital number, since it uses as much as digits as its factorization.

773145721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41160, while the sum is 37.

The square root of 773145721 is about 27805.4980354605. The cubic root of 773145721 is about 917.8121139650.

The spelling of 773145721 in words is "seven hundred seventy-three million, one hundred forty-five thousand, seven hundred twenty-one".