642120240 has 80 divisors (see below), whose sum is σ = 2008273248. Its totient is φ = 169709568.

The previous prime is 642120223. The next prime is 642120263. The reversal of 642120240 is 42021246.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15282 + ... + 38958.

Almost surely, 2^642120240 is an apocalyptic number.

642120240 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 642120240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1004136624).

642120240 is an abundant number, since it is smaller than the sum of its proper divisors (1366153008).

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

642120240 is a wasteful number, since it uses less digits than its factorization.

642120240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23806 (or 23800 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 642120240 is about 25340.0915546886. The cubic root of 642120240 is about 862.7244767536.

Adding to 642120240 its reverse (42021246), we get a palindrome (684141486).

The spelling of 642120240 in words is "six hundred forty-two million, one hundred twenty thousand, two hundred forty".