639951690240 has 240 divisors, whose sum is σ = 2217256943616. Its totient is φ = 170582630400.

The previous prime is 639951690239. The next prime is 639951690269. The reversal of 639951690240 is 42096159936.

639951690240 is a `hidden beast` number, since 6 + 39 + 9 + 516 + 90 + 2 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×639951690240² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78124545 + ... + 78132735.

Almost surely, 2^639951690240 is an apocalyptic number.

639951690240 is a gapful number since it is divisible by the number (60) 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 639951690240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1108628471808).

639951690240 is an abundant number, since it is smaller than the sum of its proper divisors (1577305253376).

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

639951690240 is a wasteful number, since it uses less digits than its factorization.

639951690240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11611 (or 11592 counting only the distinct ones).

The product of its (nonzero) digits is 3149280, while the sum is 54.

The spelling of 639951690240 in words is "six hundred thirty-nine billion, nine hundred fifty-one million, six hundred ninety thousand, two hundred forty".