639508195872 has 480 divisors, whose sum is σ = 2323636761600. Its totient is φ = 168017836032.

The previous prime is 639508195849. The next prime is 639508195951. The reversal of 639508195872 is 278591805936.

639508195872 is a `hidden beast` number, since 6 + 3 + 9 + 508 + 1 + 9 + 58 + 72 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 63444529 + ... + 63454607.

It is an arithmetic number, because the mean of its divisors is an integer number (4840909920).

Almost surely, 2^639508195872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639508195872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1161818380800).

639508195872 is an abundant number, since it is smaller than the sum of its proper divisors (1684128565728).

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

639508195872 is a wasteful number, since it uses less digits than its factorization.

639508195872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10390 (or 10373 counting only the distinct ones).

The product of its (nonzero) digits is 32659200, while the sum is 63.

The spelling of 639508195872 in words is "six hundred thirty-nine billion, five hundred eight million, one hundred ninety-five thousand, eight hundred seventy-two".