742808309 has 2 divisors, whose sum is σ = 742808310. Its totient is φ = 742808308.

The previous prime is 742808279. The next prime is 742808321. The reversal of 742808309 is 903808247.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 683979409 + 58828900 = 26153^2 + 7670^2 .

It is a cyclic number.

It is not a de Polignac number, because 742808309 - 2¹² = 742804213 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (742808399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 371404154 + 371404155.

It is an arithmetic number, because the mean of its divisors is an integer number (371404155).

Almost surely, 2^742808309 is an apocalyptic number.

It is an amenable number.

742808309 is a deficient number, since it is larger than the sum of its proper divisors (1).

742808309 is an equidigital number, since it uses as much as digits as its factorization.

742808309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 742808309 is about 27254.5098836871. The cubic root of 742808309 is about 905.6469267170.

The spelling of 742808309 in words is "seven hundred forty-two million, eight hundred eight thousand, three hundred nine".