640106244 has 18 divisors (see below), whose sum is σ = 1618046430. Its totient is φ = 213368736.

The previous prime is 640106237. The next prime is 640106279. The reversal of 640106244 is 442601046.

640106244 is a `hidden beast` number, since 640 + 10 + 6 + 2 + 4 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 457532100 + 182574144 = 21390^2 + 13512^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8890329 + ... + 8890400.

Almost surely, 2^640106244 is an apocalyptic number.

It is an amenable number.

640106244 is an abundant number, since it is smaller than the sum of its proper divisors (977940186).

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

640106244 is a wasteful number, since it uses less digits than its factorization.

640106244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17780739 (or 17780734 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 640106244 is about 25300.3210256313. The cubic root of 640106244 is about 861.8215599907.

The spelling of 640106244 in words is "six hundred forty million, one hundred six thousand, two hundred forty-four".