638879145 has 16 divisors (see below), whose sum is σ = 1024454400. Its totient is φ = 339986304.

The previous prime is 638879107. The next prime is 638879173. The reversal of 638879145 is 541978836.

It is not a de Polignac number, because 638879145 - 2⁹ = 638878633 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39745 + ... + 53454.

It is an arithmetic number, because the mean of its divisors is an integer number (64028400).

Almost surely, 2^638879145 is an apocalyptic number.

It is an amenable number.

638879145 is a deficient number, since it is larger than the sum of its proper divisors (385575255).

638879145 is a wasteful number, since it uses less digits than its factorization.

638879145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93664.

The product of its digits is 1451520, while the sum is 51.

The square root of 638879145 is about 25276.0587315349. The cubic root of 638879145 is about 861.2704968499.

It can be divided in two parts, 6388791 and 45, that added together give a palindrome (6388836).

The spelling of 638879145 in words is "six hundred thirty-eight million, eight hundred seventy-nine thousand, one hundred forty-five".