641628138240 has 360 divisors, whose sum is σ = 2297830894128. Its totient is φ = 170954219520.

The previous prime is 641628138197. The next prime is 641628138257. The reversal of 641628138240 is 42831826146.

641628138240 is a `hidden beast` number, since 6 + 4 + 1 + 628 + 13 + 8 + 2 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (360).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 179675655 + ... + 179679225.

Almost surely, 2^641628138240 is an apocalyptic number.

641628138240 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 641628138240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1148915447064).

641628138240 is an abundant number, since it is smaller than the sum of its proper divisors (1656202755888).

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

641628138240 is a wasteful number, since it uses less digits than its factorization.

641628138240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5337 (or 5314 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The spelling of 641628138240 in words is "six hundred forty-one billion, six hundred twenty-eight million, one hundred thirty-eight thousand, two hundred forty".