65639942100 has 216 divisors, whose sum is σ = 207443498808. Its totient is φ = 17360179200.

The previous prime is 65639942047. The next prime is 65639942101. The reversal of 65639942100 is 124993656.

65639942100 is a `hidden beast` number, since 6 + 5 + 639 + 9 + 4 + 2 + 1 + 0 + 0 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 40299759504 + 25340182596 = 200748^2 + 159186^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65639942101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 70052832 + ... + 70053768.

Almost surely, 2^65639942100 is an apocalyptic number.

65639942100 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 65639942100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103721749404).

65639942100 is an abundant number, since it is smaller than the sum of its proper divisors (141803556708).

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

65639942100 is a wasteful number, since it uses less digits than its factorization.

65639942100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1515 (or 1505 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 45.

The spelling of 65639942100 in words is "sixty-five billion, six hundred thirty-nine million, nine hundred forty-two thousand, one hundred".