1643664134548 has 6 divisors (see below), whose sum is σ = 2876412235466. Its totient is φ = 821832067272.

The previous prime is 1643664134507. The next prime is 1643664134549. The reversal of 1643664134548 is 8454314663461.

It can be written as a sum of positive squares in only one way, i.e., 1351201657744 + 292462476804 = 1162412^2 + 540798^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643664134549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205458016815 + ... + 205458016822.

Almost surely, 2^{1643664134548} is an apocalyptic number.

It is an amenable number.

1643664134548 is a deficient number, since it is larger than the sum of its proper divisors (1232748100918).

1643664134548 is a wasteful number, since it uses less digits than its factorization.

1643664134548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410916033641 (or 410916033639 counting only the distinct ones).

The product of its digits is 19906560, while the sum is 55.

The spelling of 1643664134548 in words is "one trillion, six hundred forty-three billion, six hundred sixty-four million, one hundred thirty-four thousand, five hundred forty-eight".