638711061 has 4 divisors (see below), whose sum is σ = 851614752. Its totient is φ = 425807372.

The previous prime is 638711027. The next prime is 638711069. The reversal of 638711061 is 160117836.

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 638711061 - 2⁹ = 638710549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638711069) 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, 106451841 + ... + 106451846.

It is an arithmetic number, because the mean of its divisors is an integer number (212903688).

Almost surely, 2^638711061 is an apocalyptic number.

It is an amenable number.

638711061 is a deficient number, since it is larger than the sum of its proper divisors (212903691).

638711061 is a wasteful number, since it uses less digits than its factorization.

638711061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212903690.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 638711061 is about 25272.7335482334. The cubic root of 638711061 is about 861.1949590956.

Adding to 638711061 its reverse (160117836), we get a palindrome (798828897).

The spelling of 638711061 in words is "six hundred thirty-eight million, seven hundred eleven thousand, sixty-one".