642163878720 has 3360 divisors, whose sum is σ = 3178534867200. Its totient is φ = 121398165504.

The previous prime is 642163878677. The next prime is 642163878721. The reversal of 642163878720 is 27878361246.

642163878720 is a `hidden beast` number, since 6 + 421 + 63 + 87 + 87 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3360).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642163878721) by changing a digit.

It is a polite number, since it can be written in 479 ways as a sum of consecutive naturals, for example, 7215324436 + ... + 7215324524.

It is an arithmetic number, because the mean of its divisors is an integer number (945992520).

Almost surely, 2^642163878720 is an apocalyptic number.

642163878720 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 642163878720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1589267433600).

642163878720 is an abundant number, since it is smaller than the sum of its proper divisors (2536370988480).

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

642163878720 is a wasteful number, since it uses less digits than its factorization.

642163878720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 5419008, while the sum is 54.

The spelling of 642163878720 in words is "six hundred forty-two billion, one hundred sixty-three million, eight hundred seventy-eight thousand, seven hundred twenty".