642123465984 has 1728 divisors, whose sum is σ = 2628538214400. Its totient is φ = 151346257920.

The previous prime is 642123465917. The next prime is 642123465989. The reversal of 642123465984 is 489564321246.

642123465984 is a `hidden beast` number, since 6 + 4 + 2 + 1 + 2 + 3 + 46 + 598 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

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

It is a self number, because there is not a number n which added to its sum of digits gives 642123465984.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642123465989) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 10883448547 + ... + 10883448605.

It is an arithmetic number, because the mean of its divisors is an integer number (1521144800).

Almost surely, 2^642123465984 is an apocalyptic number.

642123465984 is a gapful number since it is divisible by the number (64) 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 642123465984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1314269107200).

642123465984 is an abundant number, since it is smaller than the sum of its proper divisors (1986414748416).

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

642123465984 is a wasteful number, since it uses less digits than its factorization.

642123465984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150 (or 95 counting only the distinct ones).

The product of its digits is 9953280, while the sum is 54.

The spelling of 642123465984 in words is "six hundred forty-two billion, one hundred twenty-three million, four hundred sixty-five thousand, nine hundred eighty-four".