745138609 has 2 divisors, whose sum is σ = 745138610. Its totient is φ = 745138608.

The previous prime is 745138579. The next prime is 745138649. The reversal of 745138609 is 906831547.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 616429584 + 128709025 = 24828^2 + 11345^2 .

It is an emirp because it is prime and its reverse (906831547) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 745138609 - 2²⁵ = 711584177 is a prime.

It is not a weakly prime, because it can be changed into another prime (745138649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 372569304 + 372569305.

It is an arithmetic number, because the mean of its divisors is an integer number (372569305).

Almost surely, 2^745138609 is an apocalyptic number.

It is an amenable number.

745138609 is a deficient number, since it is larger than the sum of its proper divisors (1).

745138609 is an equidigital number, since it uses as much as digits as its factorization.

745138609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 181440, while the sum is 43.

The square root of 745138609 is about 27297.2271302416. The cubic root of 745138609 is about 906.5929877381.

The spelling of 745138609 in words is "seven hundred forty-five million, one hundred thirty-eight thousand, six hundred nine".