644362254020670 has 32 divisors (see below), whose sum is σ = 1546540549234560. Its totient is φ = 171822030007200.

The previous prime is 644362254020669. The next prime is 644362254020687. The reversal of 644362254020670 is 76020452263446.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 493361856 + ... + 494666195.

It is an arithmetic number, because the mean of its divisors is an integer number (48329392163580).

Almost surely, 2^{644362254020670} is an apocalyptic number.

644362254020670 is an abundant number, since it is smaller than the sum of its proper divisors (902178295213890).

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

644362254020670 is a wasteful number, since it uses less digits than its factorization.

644362254020670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 988049800.

The product of its (nonzero) digits is 11612160, while the sum is 51.

The spelling of 644362254020670 in words is "six hundred forty-four trillion, three hundred sixty-two billion, two hundred fifty-four million, twenty thousand, six hundred seventy".