639863323475376 has 640 divisors, whose sum is σ = 2253834621351936. Its totient is φ = 151040108298240.

The previous prime is 639863323475359. The next prime is 639863323475381. The reversal of 639863323475376 is 673574323368936.

It is a junction number, because it is equal to n+sod(n) for n = 639863323475298 and 639863323475307.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1953515970 + ... + 1953843486.

Almost surely, 2^{639863323475376} is an apocalyptic number.

639863323475376 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639863323475376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1126917310675968).

639863323475376 is an abundant number, since it is smaller than the sum of its proper divisors (1613971297876560).

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

639863323475376 is a wasteful number, since it uses less digits than its factorization.

639863323475376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328189 (or 328183 counting only the distinct ones).

The product of its digits is 7407106560, while the sum is 75.

The spelling of 639863323475376 in words is "six hundred thirty-nine trillion, eight hundred sixty-three billion, three hundred twenty-three million, four hundred seventy-five thousand, three hundred seventy-six".