644220622006064 has 20 divisors (see below), whose sum is σ = 1248735424564704. Its totient is φ = 321966318892608.

The previous prime is 644220622006037. The next prime is 644220622006109. The reversal of 644220622006064 is 460600226022446.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8999469992 + ... + 8999541575.

Almost surely, 2^{644220622006064} is an apocalyptic number.

It is an amenable number.

644220622006064 is a deficient number, since it is larger than the sum of its proper divisors (604514802558640).

644220622006064 is a wasteful number, since it uses less digits than its factorization.

644220622006064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17999013812 (or 17999013806 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 44.

The spelling of 644220622006064 in words is "six hundred forty-four trillion, two hundred twenty billion, six hundred twenty-two million, six thousand, sixty-four".