642351840 has 192 divisors, whose sum is σ = 2192666112. Its totient is φ = 157132800.

The previous prime is 642351833. The next prime is 642351859. The reversal of 642351840 is 48153246.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1940475 + ... + 1940805.

It is an arithmetic number, because the mean of its divisors is an integer number (11420136).

Almost surely, 2^642351840 is an apocalyptic number.

642351840 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 642351840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1096333056).

642351840 is an abundant number, since it is smaller than the sum of its proper divisors (1550314272).

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

642351840 is a wasteful number, since it uses less digits than its factorization.

642351840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673 (or 665 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 642351840 is about 25344.6609762293. The cubic root of 642351840 is about 862.8281868062.

The spelling of 642351840 in words is "six hundred forty-two million, three hundred fifty-one thousand, eight hundred forty".