638716814 has 4 divisors (see below), whose sum is σ = 958075224. Its totient is φ = 319358406.

The previous prime is 638716811. The next prime is 638716847. The reversal of 638716814 is 418617836.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638716811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159679202 + ... + 159679205.

It is an arithmetic number, because the mean of its divisors is an integer number (239518806).

Almost surely, 2^638716814 is an apocalyptic number.

638716814 is a deficient number, since it is larger than the sum of its proper divisors (319358410).

638716814 is a wasteful number, since it uses less digits than its factorization.

638716814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319358409.

The product of its digits is 193536, while the sum is 44.

The square root of 638716814 is about 25272.8473662941. The cubic root of 638716814 is about 861.1975447404.

The spelling of 638716814 in words is "six hundred thirty-eight million, seven hundred sixteen thousand, eight hundred fourteen".