642041640 has 160 divisors (see below), whose sum is σ = 2189151360. Its totient is φ = 168739200.

The previous prime is 642041633. The next prime is 642041657. The reversal of 642041640 is 46140246.

642041640 is a `hidden beast` number, since 642 + 0 + 4 + 16 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 228645 + ... + 231435.

It is an arithmetic number, because the mean of its divisors is an integer number (13682196).

Almost surely, 2^642041640 is an apocalyptic number.

642041640 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 642041640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1094575680).

642041640 is an abundant number, since it is smaller than the sum of its proper divisors (1547109720).

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

642041640 is a wasteful number, since it uses less digits than its factorization.

642041640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2885 (or 2872 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 642041640 is about 25338.5406051730. The cubic root of 642041640 is about 862.6892741511.

Adding to 642041640 its reverse (46140246), we get a palindrome (688181886).

The spelling of 642041640 in words is "six hundred forty-two million, forty-one thousand, six hundred forty".