638369377 has 2 divisors, whose sum is σ = 638369378. Its totient is φ = 638369376.

The previous prime is 638369359. The next prime is 638369411. The reversal of 638369377 is 773963836.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 613008081 + 25361296 = 24759^2 + 5036^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638369377 is a prime.

It is a super-2 number, since 2×638369377² = 815030922982736258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (638369077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319184688 + 319184689.

It is an arithmetic number, because the mean of its divisors is an integer number (319184689).

Almost surely, 2^638369377 is an apocalyptic number.

It is an amenable number.

638369377 is a deficient number, since it is larger than the sum of its proper divisors (1).

638369377 is an equidigital number, since it uses as much as digits as its factorization.

638369377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3429216, while the sum is 52.

The square root of 638369377 is about 25265.9727103470. The cubic root of 638369377 is about 861.0413638089.

The spelling of 638369377 in words is "six hundred thirty-eight million, three hundred sixty-nine thousand, three hundred seventy-seven".