638147765 has 8 divisors (see below), whose sum is σ = 799072128. Its totient is φ = 488321680.

The previous prime is 638147761. The next prime is 638147773. The reversal of 638147765 is 567741836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 638147765 - 2² = 638147761 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 (638147761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2774441 + ... + 2774670.

It is an arithmetic number, because the mean of its divisors is an integer number (99884016).

Almost surely, 2^638147765 is an apocalyptic number.

It is an amenable number.

638147765 is a deficient number, since it is larger than the sum of its proper divisors (160924363).

638147765 is a wasteful number, since it uses less digits than its factorization.

638147765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5549139.

The product of its digits is 846720, while the sum is 47.

The square root of 638147765 is about 25261.5867474710. The cubic root of 638147765 is about 860.9417145093.

The spelling of 638147765 in words is "six hundred thirty-eight million, one hundred forty-seven thousand, seven hundred sixty-five".