638910141 has 4 divisors (see below), whose sum is σ = 851880192. Its totient is φ = 425940092.

The previous prime is 638910121. The next prime is 638910197. The reversal of 638910141 is 141019836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 638910141 - 2⁵ = 638910109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638910101) 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, 106485021 + ... + 106485026.

It is an arithmetic number, because the mean of its divisors is an integer number (212970048).

Almost surely, 2^638910141 is an apocalyptic number.

It is an amenable number.

638910141 is a deficient number, since it is larger than the sum of its proper divisors (212970051).

638910141 is a wasteful number, since it uses less digits than its factorization.

638910141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212970050.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 638910141 is about 25276.6718734884. The cubic root of 638910141 is about 861.2844251538.

Adding to 638910141 its reverse (141019836), we get a palindrome (779929977).

The spelling of 638910141 in words is "six hundred thirty-eight million, nine hundred ten thousand, one hundred forty-one".