1644623636164 has 6 divisors (see below), whose sum is σ = 2878091363294. Its totient is φ = 822311818080.

The previous prime is 1644623636119. The next prime is 1644623636177. The reversal of 1644623636164 is 4616363264461.

It can be written as a sum of positive squares in only one way, i.e., 1396627604100 + 247996032064 = 1181790^2 + 497992^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205577954517 + ... + 205577954524.

Almost surely, 2^{1644623636164} is an apocalyptic number.

It is an amenable number.

1644623636164 is a deficient number, since it is larger than the sum of its proper divisors (1233467727130).

1644623636164 is a wasteful number, since it uses less digits than its factorization.

1644623636164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411155909045 (or 411155909043 counting only the distinct ones).

The product of its digits is 8957952, while the sum is 52.

The spelling of 1644623636164 in words is "one trillion, six hundred forty-four billion, six hundred twenty-three million, six hundred thirty-six thousand, one hundred sixty-four".