642819840 has 288 divisors, whose sum is σ = 2252651520. Its totient is φ = 155271168.

The previous prime is 642819797. The next prime is 642819851. The reversal of 642819840 is 48918246.

It is a junction number, because it is equal to n+sod(n) for n = 642819792 and 642819801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3943599 + ... + 3943761.

Almost surely, 2^642819840 is an apocalyptic number.

642819840 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 642819840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1126325760).

642819840 is an abundant number, since it is smaller than the sum of its proper divisors (1609831680).

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

642819840 is a wasteful number, since it uses less digits than its factorization.

642819840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279 (or 265 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 42.

The square root of 642819840 is about 25353.8920089204. The cubic root of 642819840 is about 863.0376802848.

The spelling of 642819840 in words is "six hundred forty-two million, eight hundred nineteen thousand, eight hundred forty".