642423240 has 96 divisors (see below), whose sum is σ = 2109514680. Its totient is φ = 169537536.

The previous prime is 642423239. The next prime is 642423289. The reversal of 642423240 is 42324246.

642423240 is a `hidden beast` number, since 6 + 424 + 232 + 4 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 602506116 + 39917124 = 24546^2 + 6318^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25722 + ... + 44118.

Almost surely, 2^642423240 is an apocalyptic number.

642423240 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 642423240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1054757340).

642423240 is an abundant number, since it is smaller than the sum of its proper divisors (1467091440).

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

642423240 is a wasteful number, since it uses less digits than its factorization.

642423240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18511 (or 18504 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

The square root of 642423240 is about 25346.0695177773. The cubic root of 642423240 is about 862.8601545671.

Adding to 642423240 its reverse (42324246), we get a palindrome (684747486).

The spelling of 642423240 in words is "six hundred forty-two million, four hundred twenty-three thousand, two hundred forty".