638074009 has 2 divisors, whose sum is σ = 638074010. Its totient is φ = 638074008.

The previous prime is 638073973. The next prime is 638074013. The reversal of 638074009 is 900470836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 637714009 + 360000 = 25253^2 + 600^2 .

It is a cyclic number.

It is not a de Polignac number, because 638074009 - 2⁷ = 638073881 is a prime.

It is a super-2 number, since 2×638074009² = 814276881922664162, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (638074069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319037004 + 319037005.

It is an arithmetic number, because the mean of its divisors is an integer number (319037005).

Almost surely, 2^638074009 is an apocalyptic number.

It is an amenable number.

638074009 is a deficient number, since it is larger than the sum of its proper divisors (1).

638074009 is an equidigital number, since it uses as much as digits as its factorization.

638074009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 638074009 is about 25260.1268603307. The cubic root of 638074009 is about 860.9085445200.

The spelling of 638074009 in words is "six hundred thirty-eight million, seventy-four thousand, nine".