638723956103 has 4 divisors (see below), whose sum is σ = 643753278720. Its totient is φ = 633694633488.

The previous prime is 638723956081. The next prime is 638723956163. The reversal of 638723956103 is 301659327836.

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-638723956103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638723956163) 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, 2514661118 + ... + 2514661371.

It is an arithmetic number, because the mean of its divisors is an integer number (160938319680).

Almost surely, 2^638723956103 is an apocalyptic number.

638723956103 is a deficient number, since it is larger than the sum of its proper divisors (5029322617).

638723956103 is a wasteful number, since it uses less digits than its factorization.

638723956103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5029322616.

The product of its (nonzero) digits is 4898880, while the sum is 53.

The spelling of 638723956103 in words is "six hundred thirty-eight billion, seven hundred twenty-three million, nine hundred fifty-six thousand, one hundred three".