642448890 has 96 divisors (see below), whose sum is σ = 1742083200. Its totient is φ = 164062080.

The previous prime is 642448847. The next prime is 642448897. The reversal of 642448890 is 98844246.

642448890 is a `hidden beast` number, since 64 + 24 + 488 + 90 = 666.

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 (642448897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 340971 + ... + 342849.

It is an arithmetic number, because the mean of its divisors is an integer number (18146700).

Almost surely, 2^642448890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642448890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (871041600).

642448890 is an abundant number, since it is smaller than the sum of its proper divisors (1099634310).

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

642448890 is a wasteful number, since it uses less digits than its factorization.

642448890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2052 (or 2049 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The square root of 642448890 is about 25346.5755083404. The cubic root of 642448890 is about 862.8716382054.

The spelling of 642448890 in words is "six hundred forty-two million, four hundred forty-eight thousand, eight hundred ninety".