638613782670 has 16 divisors (see below), whose sum is σ = 1532673078480. Its totient is φ = 170297008704.

The previous prime is 638613782669. The next prime is 638613782671. The reversal of 638613782670 is 76287316836.

It is an interprime number because it is at equal distance from previous prime (638613782669) and next prime (638613782671).

It is a self number, because there is not a number n which added to its sum of digits gives 638613782670.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638613782671) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10643563015 + ... + 10643563074.

It is an arithmetic number, because the mean of its divisors is an integer number (95792067405).

Almost surely, 2^638613782670 is an apocalyptic number.

638613782670 is an abundant number, since it is smaller than the sum of its proper divisors (894059295810).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638613782670 is a wasteful number, since it uses less digits than its factorization.

638613782670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21287126099.

The product of its (nonzero) digits is 12192768, while the sum is 57.

The spelling of 638613782670 in words is "six hundred thirty-eight billion, six hundred thirteen million, seven hundred eighty-two thousand, six hundred seventy".