638468287 has 4 divisors (see below), whose sum is σ = 646160760. Its totient is φ = 630775816.

The previous prime is 638468279. The next prime is 638468291. The reversal of 638468287 is 782864836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 638468287 - 2³ = 638468279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638468227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3846112 + ... + 3846277.

It is an arithmetic number, because the mean of its divisors is an integer number (161540190).

Almost surely, 2^638468287 is an apocalyptic number.

638468287 is a deficient number, since it is larger than the sum of its proper divisors (7692473).

638468287 is an equidigital number, since it uses as much as digits as its factorization.

638468287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7692472.

The product of its digits is 3096576, while the sum is 52.

The square root of 638468287 is about 25267.9300101928. The cubic root of 638468287 is about 861.0858319001.

The spelling of 638468287 in words is "six hundred thirty-eight million, four hundred sixty-eight thousand, two hundred eighty-seven".