642786100 has 72 divisors (see below), whose sum is σ = 1554150528. Its totient is φ = 228748800.

The previous prime is 642786091. The next prime is 642786101. The reversal of 642786100 is 1687246.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642786101) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 45484 + ... + 57916.

It is an arithmetic number, because the mean of its divisors is an integer number (21585424).

Almost surely, 2^642786100 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642786100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (777075264).

642786100 is an abundant number, since it is smaller than the sum of its proper divisors (911364428).

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

642786100 is a wasteful number, since it uses less digits than its factorization.

642786100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12505 (or 12498 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 642786100 is about 25353.2266191110. The cubic root of 642786100 is about 863.0225804600.

The spelling of 642786100 in words is "six hundred forty-two million, seven hundred eighty-six thousand, one hundred".