642889094400 has 810 divisors, whose sum is σ = 2765253591870. Its totient is φ = 146940272640.

The previous prime is 642889094387. The next prime is 642889094417. The reversal of 642889094400 is 4490988246.

642889094400 is a `hidden beast` number, since 6 + 428 + 8 + 90 + 94 + 40 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 57553929216 + 585335165184 = 239904^2 + 765072^2 .

It is a tau number, because it is divible by the number of its divisors (810).

It is a super-2 number, since 2×642889094400² (a number of 24 digits) contains 22 as substring.

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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 25388946 + ... + 25414254.

Almost surely, 2^642889094400 is an apocalyptic number.

642889094400 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 642889094400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1382626795935).

642889094400 is an abundant number, since it is smaller than the sum of its proper divisors (2122364497470).

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

642889094400 is a wasteful number, since it uses less digits than its factorization.

642889094400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25361 (or 25326 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 54.

The spelling of 642889094400 in words is "six hundred forty-two billion, eight hundred eighty-nine million, ninety-four thousand, four hundred".