638113471 has 4 divisors (see below), whose sum is σ = 639014200. Its totient is φ = 637212744.

The previous prime is 638113459. The next prime is 638113519. The reversal of 638113471 is 174311836.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638113471 is a prime.

It is a super-3 number, since 3×638113471³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638113451) 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, 449301 + ... + 450718.

It is an arithmetic number, because the mean of its divisors is an integer number (159753550).

Almost surely, 2^638113471 is an apocalyptic number.

638113471 is a deficient number, since it is larger than the sum of its proper divisors (900729).

638113471 is an equidigital number, since it uses as much as digits as its factorization.

638113471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900728.

The product of its digits is 12096, while the sum is 34.

The square root of 638113471 is about 25260.9079607207. The cubic root of 638113471 is about 860.9262919245.

The spelling of 638113471 in words is "six hundred thirty-eight million, one hundred thirteen thousand, four hundred seventy-one".