642912655680 has 1120 divisors, whose sum is σ = 2531675139840. Its totient is φ = 154302382080.

The previous prime is 642912655621. The next prime is 642912655691. The reversal of 642912655680 is 86556219246.

642912655680 is a `hidden beast` number, since 6 + 4 + 2 + 9 + 1 + 2 + 6 + 556 + 80 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 708833787 + ... + 708834693.

It is an arithmetic number, because the mean of its divisors is an integer number (2260424232).

Almost surely, 2^642912655680 is an apocalyptic number.

642912655680 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 642912655680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1265837569920).

642912655680 is an abundant number, since it is smaller than the sum of its proper divisors (1888762484160).

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

642912655680 is a wasteful number, since it uses less digits than its factorization.

642912655680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1029 (or 1010 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 54.

The spelling of 642912655680 in words is "six hundred forty-two billion, nine hundred twelve million, six hundred fifty-five thousand, six hundred eighty".