644100694166 has 4 divisors (see below), whose sum is σ = 966151041252. Its totient is φ = 322050347082.

The previous prime is 644100694117. The next prime is 644100694217. The reversal of 644100694166 is 661496001446.

644100694166 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 644100694166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161025173540 + ... + 161025173543.

It is an arithmetic number, because the mean of its divisors is an integer number (241537760313).

Almost surely, 2^644100694166 is an apocalyptic number.

644100694166 is a deficient number, since it is larger than the sum of its proper divisors (322050347086).

644100694166 is a wasteful number, since it uses less digits than its factorization.

644100694166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322050347085.

The product of its (nonzero) digits is 746496, while the sum is 47.

The spelling of 644100694166 in words is "six hundred forty-four billion, one hundred million, six hundred ninety-four thousand, one hundred sixty-six".