644534213163604 has 48 divisors (see below), whose sum is σ = 1168782701363200. Its totient is φ = 310676319784800.

The previous prime is 644534213163583. The next prime is 644534213163611. The reversal of 644534213163604 is 406361312435446.

It is a happy number.

It is a super-2 number, since 2×644534213163604² (a number of 30 digits) contains 22 as substring.

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, 235176127 + ... + 237900985.

Almost surely, 2^{644534213163604} is an apocalyptic number.

It is an amenable number.

644534213163604 is a deficient number, since it is larger than the sum of its proper divisors (524248488199596).

644534213163604 is a wasteful number, since it uses less digits than its factorization.

644534213163604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2732204 (or 2732202 counting only the distinct ones).

The product of its (nonzero) digits is 14929920, while the sum is 52.

The spelling of 644534213163604 in words is "six hundred forty-four trillion, five hundred thirty-four billion, two hundred thirteen million, one hundred sixty-three thousand, six hundred four".