638393453 has 2 divisors, whose sum is σ = 638393454. Its totient is φ = 638393452.

The previous prime is 638393429. The next prime is 638393467. The reversal of 638393453 is 354393836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 568202569 + 70190884 = 23837^2 + 8378^2 .

It is a cyclic number.

It is not a de Polignac number, because 638393453 - 2¹⁰ = 638392429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638393423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319196726 + 319196727.

It is an arithmetic number, because the mean of its divisors is an integer number (319196727).

Almost surely, 2^638393453 is an apocalyptic number.

It is an amenable number.

638393453 is a deficient number, since it is larger than the sum of its proper divisors (1).

638393453 is an equidigital number, since it uses as much as digits as its factorization.

638393453 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 44.

The square root of 638393453 is about 25266.4491569354. The cubic root of 638393453 is about 861.0521883524.

The spelling of 638393453 in words is "six hundred thirty-eight million, three hundred ninety-three thousand, four hundred fifty-three".