642746880 has 320 divisors, whose sum is σ = 2421809280. Its totient is φ = 161021952.

The previous prime is 642746861. The next prime is 642746887. The reversal of 642746880 is 88647246.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (642746887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1174767 + ... + 1175313.

It is an arithmetic number, because the mean of its divisors is an integer number (7568154).

Almost surely, 2^642746880 is an apocalyptic number.

642746880 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 642746880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1210904640).

642746880 is an abundant number, since it is smaller than the sum of its proper divisors (1779062400).

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

642746880 is a wasteful number, since it uses less digits than its factorization.

642746880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596 (or 574 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 45.

The square root of 642746880 is about 25352.4531357421. The cubic root of 642746880 is about 863.0050274804.

The spelling of 642746880 in words is "six hundred forty-two million, seven hundred forty-six thousand, eight hundred eighty".