638489740415 has 4 divisors (see below), whose sum is σ = 766187688504. Its totient is φ = 510791792328.

The previous prime is 638489740411. The next prime is 638489740433. The reversal of 638489740415 is 514047984836.

638489740415 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 638489740415 - 2² = 638489740411 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 (638489740411) 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, 63848974037 + ... + 63848974046.

It is an arithmetic number, because the mean of its divisors is an integer number (191546922126).

Almost surely, 2^638489740415 is an apocalyptic number.

638489740415 is a deficient number, since it is larger than the sum of its proper divisors (127697948089).

638489740415 is a wasteful number, since it uses less digits than its factorization.

638489740415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127697948088.

The product of its (nonzero) digits is 23224320, while the sum is 59.

The spelling of 638489740415 in words is "six hundred thirty-eight billion, four hundred eighty-nine million, seven hundred forty thousand, four hundred fifteen".