644064622 has 8 divisors (see below), whose sum is σ = 1016944200. Its totient is φ = 305083224.

The previous prime is 644064599. The next prime is 644064623. The reversal of 644064622 is 226460446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644064623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8474497 + ... + 8474572.

It is an arithmetic number, because the mean of its divisors is an integer number (127118025).

Almost surely, 2^644064622 is an apocalyptic number.

644064622 is a deficient number, since it is larger than the sum of its proper divisors (372879578).

644064622 is a wasteful number, since it uses less digits than its factorization.

644064622 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16949090.

The product of its (nonzero) digits is 55296, while the sum is 34.

The square root of 644064622 is about 25378.4282807269. The cubic root of 644064622 is about 863.5943946304.

The spelling of 644064622 in words is "six hundred forty-four million, sixty-four thousand, six hundred twenty-two".